TY - JOUR A1 - Srivastava, Priyanka A1 - Fürstenwerth, Paul Christian A1 - Witte, J. F. A1 - Resch-Genger, Ute T1 - Synthesis and spectroscopic characterization of a fluorescent phenanthrene-rhodamine dyad for ratiometric measurements of acid pH values N2 - We present the rational design, synthesis and spectroscopic characterization of a novel dual excitation, three color emitting, pH-responsive fluorescent probe consisting of two phenanthrene and one rhodamine B units linked by click chemistry. The rhodamine moiety, excitable at λEx = 315 nm and at λEx = 560 nm in its ring-opened form, provides the pH-responsive fluorophore, while the pH-insensitive phenanthrene, excited at λEx = 315 nm, serves as inert internal reference, The presence of two phenanthrene moieties enables a blue monomer and a blueish green excimer emission at 351 nm and 500 nm, respectively. Opening of the rhodamine B spirolactam ring at an acidic pH below 5.0 (pKa = 2.59 ± 0.04) switches on its emission at 580 nm. Simultaneously, the phenanthrene excimer emission decreases caused by a change in orientation of the phenanthrene units, while the monomer emission is barely affected. This sensor design enables ratiometric measurements in the low acidic pH range utilizing the intensity ratios of the rhodamine B and phenanthrene excimer emission at 580 nm and 500 nm. Alternatively, also the intensity ratios of the rhodamine B and the phenanthrene monomer emission could be exploited or the sum of the phenanthrene monomer and excimer fluorescence. To the best of our knowledge, this is the first report of ratiometric sensing utilizing such a versatile type of tricolor emissive dyad probe bearing phenanthrene moieties and showing phenanthrene monomer and excimer emission. KW - Fluorescence KW - Optical probe KW - Sensor KW - Dye KW - Rhodamine KW - Synthesis KW - Photophysics KW - PH KW - Quantum yield KW - Quality assurance KW - Mechanism KW - Chemodosimeter KW - Phenanthrene KW - Ratiometric KW - Dyad PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530554 DO - https://doi.org/10.1039/d1nj01573g SN - 1144-0546 VL - 45 IS - 31 SP - 13755 EP - 13762 PB - Royal Society of Chemistry AN - OPUS4-53055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andresen, Elina A1 - Radunz, Sebastian A1 - Resch-Genger, Ute T1 - Novel PET-Operated Rosamine Sensor Dyes with Substitution Pattern-Tunable pKa Values and Temperature Sensitivity N2 - We present the synthesis and characterization of a family of regioisomerically pure pH-sensitive rosamine fluorophores consisting of xanthene fluorophore cores, which determine the dyes’ photophysical properties such as excitation/emission wavelength, fluorescence quantum yield, and fluorescence lifetime, and differently substituted phenol moieties. The hydroxyl substituent of the phenol moiety introduces a pH sensitivity of the dyes’ fluorescence exploiting a photoinduced electron transfer (PET), that leads to a protonation-induced switching ON of the rosamine emission. Rational tuning of the pKa value of the rosamine fluorescence between 4 to 9 is achieved by altering the substitution pattern and degree of bromination of the phenolic subunits. Additionally, a temperature sensitivity of the fluorescence quantum yield is introduced or suppressed based upon the degree of rigidity of the xanthene scaffold. KW - Fluorescence KW - Optical probe KW - Sensor KW - Dye KW - Rosamine KW - Synthesis KW - Photophysics KW - PH KW - Quantum yield KW - Quality assurancemechanism KW - temperature PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530562 DO - https://doi.org/10.1039/d1nj02505h VL - 45 IS - 31 SP - 13934 EP - 13940 PB - Royal Society of Chemistry AN - OPUS4-53056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nelson, G. A1 - Boehm, U. A1 - Bagley, S. A1 - Bajcsy, P. A1 - Bischof, J. A1 - Brown, C. M. A1 - Dauphin, A. A1 - Dobbie, I. M. A1 - Eriksson, J. E. A1 - Faklaris, O. A1 - Fernandez-Rodriguez, J. A1 - Ferrand, A. A1 - Gelman, L, A1 - Gheisari, A. A1 - Hartmann, H. A1 - Kukat, C. A1 - Laude, A. A1 - Mitkovski, M. A1 - Munck, S. A1 - North, A. J. A1 - Rasse, T. A1 - Resch-Genger, Ute A1 - Schuetz, L. C. A1 - Seitz, A. A1 - Strambio-De-Castillia, C. A1 - Swedlow, J. R. A1 - Alexopoulos, I. A1 - Aumayr, K. A1 - Avilov, S. A1 - Bakker, G.-J. A1 - Bammann, R. R. A1 - Bassi, A. A1 - Beckert, H. A1 - Beer, S. A1 - Belyaev, Y. A1 - Bierwagen, J. A1 - Birngruber, K. A. A1 - Bosch, M. A1 - Breitlow, J. A1 - Cameron, L. A. A1 - Chalfoun, J. A1 - Chambers, J. J. A1 - Chen, C.-L. A1 - Conde-Sousa, E. A1 - Corbett, A. D. A1 - Cordelieres, F. P. A1 - Del Nery, E. A1 - Dietzel, R. A1 - Eismann, F. A1 - Fazeli, E. A1 - Felscher, A. A1 - Fried, H. A1 - Gaudreault, N. A1 - Goh, W. I. A1 - Guilbert, T. A1 - Hadleigh, R. A1 - Hemmerich, P. A1 - Holst, G. A. A1 - Itano, M. S. A1 - Jaffe, C. B. A1 - Jambor, H. K. A1 - Jarvis, S. C. A1 - Keppler, A. A1 - Kirchenbuechler, D. A1 - Kirchner, M. A1 - Kobayashi, N. A1 - Krens, G. A1 - Kunis, S. A1 - Lacoste, J. A1 - Marcello, M. A1 - Martins, G. G. A1 - Metcalf, D. J. A1 - Mitchell, C. A. A1 - Moore, J. A1 - Mueller, T. A1 - Nelson, M. S. A1 - Ogg, S. A1 - Onami, S. A1 - Palmer, A. L. A1 - Paul-Gilloteaux, P. A1 - Pimentel, J. A. A1 - Plantard, L. A1 - Podder, S. A1 - Rexhepaj, E. A1 - Royon, A. A1 - Saari, M. A. A1 - Schapman, D. A1 - Schoonderwoert, V. A1 - Schroth-Diez, B. A1 - Schwartz, S. A1 - Shaw, M. A1 - Spitaler, M. A1 - Stoeckl, M. T. A1 - Sudar, D. A1 - Teillon, J. A1 - Terjung, S. A1 - Thuenauer, R. A1 - Wilms, C. D. A1 - Wright, G. D. A1 - Nitschke, R. T1 - QUAREP-LiMi: A community-driven initiative to establish guidelines for quality assessment and reproducibility for instruments and images in light microscopy N2 - A modern day light microscope has evolved from a tool devoted to making primarily empirical observations to what is now a sophisticated, quantitative device that is an integral part of both physical and life science research. Nowadays, microscopes are found in nearly every experimental laboratory. However, despite their prevalent use in capturing and quantifying scientific phenomena, neither a thorough understanding of the principles underlying quantitative imaging techniques nor appropriate knowledge of how to calibrate, operate and maintain microscopes can be taken for granted. This is clearly demonstrated by the well-documented and widespread difficulties that are routinely encountered in evaluating acquired data and reproducing scientific experiments. Indeed, studies have shown that more than 70% of researchers have tried and failed to repeat another scientist’s experiments, while more than half have even failed to reproduce their own experiments1. One factor behind the reproducibility crisis of experiments published in scientific journals is the frequent underreporting of imaging methods caused by a lack of awareness and/or a lack of knowledge of the applied technique2,3. Whereas quality control procedures for some methods used in biomedical research, such as genomics (e.g., DNA sequencing, RNA-seq) or cytometry, have been introduced (e.g. ENCODE4), this issue has not been tackled for optical microscopy instrumentation and images. Although many calibration standards and protocols have been published, there is a lack of awareness and agreement on common Standards and guidelines for quality assessment and reproducibility5. In April 2020, the QUality Assessment and REProducibility for instruments and images in Light Microscopy (QUAREP-LiMi) initiative6 was formed. This initiative comprises imaging scientists from academia and industry who share a common interest in achieving a better understanding of the performance and limitations of microscopes and improved quality control (QC) in light microscopy. The ultimate goal of the QUAREP-LiMi initiative is to establish a set of common QC standards, guidelines, metadata models7,8, and tools9,10, including detailed protocols, with the ultimate aim of improving reproducible advances in scientific research. This White Paper 1) summarizes the major obstacles identified in the field that motivated the launch of the QUAREP-LiMi initiative; 2) identifies the urgent need to address these obstacles in a grassroots manner, through a community of Stakeholders including, researchers, imaging scientists11, bioimage analysts, bioimage informatics developers, corporate partners, Funding agencies, standards organizations, scientific publishers, and observers of such; 3) outlines the current actions of the QUAREPLiMi initiative, and 4) proposes future steps that can be taken to improve the dissemination and acceptance of the proposed guidelines to manage QC. To summarize, the principal goal of the QUAREP-LiMi initiative is to improve the overall quality and reproducibility of light microscope image data by introducing broadly accepted standard practices and accurately captured image data metrics. KW - Fluorescence KW - Microscopy KW - Quality assurance KW - Comparability KW - Imaging KW - Standards KW - Reference materials KW - Reliability KW - Data KW - Reference data KW - Biology KW - Medicine KW - Life science PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530629 DO - https://doi.org/10.1111/jmi.13041 SN - 1365-2818 VL - 284 IS - 1 SP - 56 EP - 73 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-53062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Rurack, Knut A1 - Hecht, Mandy T1 - Loading and Release of Charged and Neutral Fluorescent Dyes into and from Mesoporous Materials: A Key Role for Sensing Applications N2 - The aim of this study is to determine the efficiency of loading and release of several zwitterionic, neutral, anionic and cationic dyes into/from mesoporous nanoparticles to find the optimum loading and release conditions for their application in detection protocols. The loading is carried out for MCM-41 type silica supports suspended in phosphate-buffered saline (PBS) buffer (pH 7.4) or in acetonitrile, involving the dyes (rhodamine B chloride, rhodamine 101 chloride, rhodamine 101 perchlorate, rhodamine 101 inner salt, meso-(4-hydroxyphenyl)-boron–dipyrromethene (BODIPY), sulforhodamine B sodium salt and fluorescein 27). As a general trend, rhodamine-based dyes are loaded with higher efficiency, when compared with BODIPY and fluorescein dyes. Between the rhodamine-based dyes, their charge and the solvent in which the loading process is carried out play important roles for the amount of cargo that can be loaded into the materials. The delivery experiments carried out in PBS buffer at pH 7.4 reveal for all the materials that anionic dyes are more efficiently released compared to their neutral or cationic counterparts. The overall best performance is achieved with the negatively charged sulforhodamine B dye in acetonitrile. This material also shows a high delivery degree in PBS buffer. KW - Mesoporous materials KW - Charged dyes KW - Neutral dyes KW - Dye loading optimisation KW - Dye release PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522596 UR - https://www.mdpi.com/2072-666X/12/3/249 DO - https://doi.org/10.3390/mi12030249 VL - 12 IS - 3 SP - 249 PB - MDPI AN - OPUS4-52259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rühle, Bastian A1 - Krumrey, Julian Frederic A1 - Hodoroaba, Vasile-Dan T1 - Workflow towards automated segmentation of agglomerated, non‑spherical particles from electron microscopy images using artificial neural networks N2 - We present a workflow for obtaining fully trained artificial neural networks that can perform automatic particle segmentations of agglomerated, non-spherical nanoparticles from scanning electron microscopy images “from scratch”, without the need for large training data sets of manually annotated images. The whole process only requires about 15 minutes of hands-on time by a user and can typically be finished within less than 12 hours when training on a single graphics card (GPU). After training, SEM image analysis can be carried out by the artificial neural network within seconds. This is achieved by using unsupervised learning for most of the training dataset generation, making heavy use of generative adversarial networks and especially unpaired image-to-image translation via cycle-consistent adversarial networks. We compare the segmentation masks obtained with our suggested workflow qualitatively and quantitatively to state-of-the-art methods using various metrics. Finally, we used the segmentation masks for automatically extracting particle size distributions from the SEM images of TiO2 particles, which were in excellent agreement with particle size distributions obtained manually but could be obtained in a fraction of the time. KW - Electron microscopy KW - Neural networks KW - Artificial intelligence KW - Image segmentation KW - Automated image analysis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522454 DO - https://doi.org/10.1038/s41598-021-84287-6 VL - 11 IS - 1 SP - 4942 PB - Springer Nature AN - OPUS4-52245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marklein, B. A1 - Jenning, M. A1 - Konthur, Zoltán A1 - Häupl, T. A1 - Welzel, F. A1 - Nonhoff, U. A1 - Krobitsch, S. A1 - Mulder, D. M. A1 - Koenders, M. I. A1 - Joshua, V. A1 - Cope, A. P. A1 - Shlomchik, M. J. A1 - Anders, H.-J. A1 - Burmester, G. R. A1 - Hensvold, A. A1 - Catrina, A. I. A1 - Rönnelid, J. A1 - Steiner, G. A1 - Skriner, K. T1 - The citrullinated/native index of autoantibodies against hnRNP-DL predicts an individual "window of treatment success" in RA patients N2 - Background: There is a need for biomarker to identify patients “at risk” for rheumatoid arthritis (risk-RA) and to better predict the therapeutic response and in this study we tested the hypothesis that novel native and citrullinated heterogeneous nuclear ribonucleoprotein (hnRNP)-DL autoantibodies could be possible biomarkers. Methods: Using protein macroarray and ELISA, epitope recognition against hnRNP-DL was analysed in sera from different developed RA disease and diagnosed SLE patients. Toll-like receptor (TLR) 7/9 and myeloid Differentiation primary response gene 88 (MyD88)-dependency were studied in sera from murine disease models. HnRNP-DL expression in cultivated cells and synovial tissue was analysed by indirect immunofluorescence, immunoblot and immunohistochemistry. KW - Citrullinated KW - Rheumatoid arthritis KW - Protein-modification KW - Autoantibodies KW - Antigens PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533682 DO - https://doi.org/10.1186/s13075-021-02603-x SN - 1478-6362 VL - 23 SP - 1 EP - 16 PB - BioMed Central CY - London AN - OPUS4-53368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haeckel, A. A1 - Ascher, Lena A1 - Beindorff, N. A1 - Prasad, S. A1 - Garczynska, K. A1 - Guo, J. A1 - Schellenberger, E. T1 - Long‑circulating XTEN864‑annexin A5 fusion protein for phosphatidylserine‑related therapeutic applications N2 - Annexin A5 (anxA5) is a marker for apoptosis, but has also therapeutic potential in cardiovascular diseases, cancer, and, due to apoptotic mimicry, against dangerous viruses, which is limited by the short blood circulation. An 864-amino-acid XTEN polypeptide was fused to anxA5. XTEN864-anxA5 was expressed in Escherichia coli and purified using XTEN as tag. XTEN864-anxA5 was coupled with DTPA and indium-111. After intravenous or subcutaneous injection of 111In-XTEN864-anxA5, mouse blood samples were collected for blood half-life determination and organ samples for biodistribution using a gamma counter. XTEN864-anxA5 was labeled with 6S-IDCC to confirm binding to apoptotic cells using flow cytometry. To demonstrate targeting of atherosclerotic plaques, XTEN864-anxA5 was labeled with MeCAT(Ho) and administered intravenously to atherosclerotic ApoE−/−mice. MeCAT(Ho)-XTEN864-anxA5 was detected together with MeCAT(Tm)-MAC-2 macrophage antibodies by imaging mass cytometry (CyTOF) of aortic root sections. The ability of anxA5 to bind apoptotic cells was not affected by XTEN864. The blood half-life of XTEN864-anxA5 was 13 h in mice after IV injection, markedly longer than the 7-min half-life of anxA5. 96 h after injection, highest amounts of XTEN864-anxA5 were found in liver, spleen, and kidney. XTEN864-anxA5 was found to target the adventitia adjacent to atherosclerotic plaques. XTEN864-anxA5 is a long-circulating fusion protein that can be efficiently produced in E. coli and potentially circulates in humans for several days, making it a promising therapeutic drug. KW - Programmed cell death KW - LA/ICP-MS Imaging KW - Medicinal application PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533811 DO - https://doi.org/10.1007/s10495-021-01686-w VL - 26 IS - 9-10 SP - 534 EP - 547 PB - Springer AN - OPUS4-53381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Xu, R. A1 - Teich, W. A1 - Frenzel, Florian A1 - Hoffmann, Katrin A1 - Radke, J. A1 - Rösler, J. A1 - Faust, K. A1 - Blank, A. A1 - Brandenburg, S. A1 - Misch, M. A1 - Vajkoczy, P. A1 - Onken, J. S. A1 - Resch-Genger, Ute T1 - Optical characterization of sodium fluorescein in vitro and ex vivo N2 - Objective: The utilization of fluorescein-guided biopsies and resection has been recently discussed as a suitable strategy to improve and expedite operative techniques for the resection of central nervous system (CNS) tumors. However, little is known about the optical properties of sodium fluorescein (NaFl) in human tumor tissue and their potential impact on ex vivo analyses involving fluorescence-based methods. Methods: Tumor tissue was obtained from a study cohort of an observational study on the utilization of fluorescein-guided biopsy and resection (n=5). The optical properties of fluorescein-stained tissue were compared to the optical features of the dye in vitro and in control samples consisting of tumor tissue of high-grade glioma patients (n=3) without intravenous (i.v.) application of NaFl. The dye-exposed tumor tissues were used for optical measurements to confirm the detectability of NaFl emission ex vivo. The tissue samples were fixed in 4%PFA, immersed in 30% sucrose, embedded in Tissue-Tek OCT compound, and cut to 10 mm cryosections. Spatially resolved emission spectra from tumor samples were recorded on representative slides with a Confocal Laser Scanning Microscope FV1000 (Olympus GmbH, Hamburg, Germany) upon excitation with lexc = 488 nm. Results: Optical measurements of fluorescein in 0.9% sodium chloride (NaCl) under in vitro conditions showed an absorption maximum of lmax abs = 479 nm as detected with spectrophotometer Specord 200 and an emission peak at lmax em = 538 nm recorded with the emCCD detection system of a custom-made microscope-based single particle setup using a 500 nm long-pass filter. Further measurements revealed pH- and concentration-dependent emission spectra of NaFl. Under ex vivo conditions, confocal laser scanning microscopy of fluorescein tumor samples revealed a slight bathochromic shift and a broadening of the emission band. Conclusion: Tumor uptake of NaFl leads to changes in the optical properties – a bathochromic shift and broadening of the emission band – possibly caused by the dye’s high pH sensitivity and concentration-dependent reabsorption acting as an innerfilter of the dye’s emission, particularly in the short wavelength region of the Emission spectrum where absorption and fluorescence overlap. Understanding the ex vivo optical properties of fluorescein is crucial for testing and validating its further applicability as an optical probe for intravital microscopy, immunofluorescence localization studies, and flow cytometry analysis. KW - Fluorescence KW - Optical probe KW - Sensor KW - Fluorescein KW - PH KW - Imaging KW - Tissue KW - Cancer KW - Medical diagnostics KW - Tumor KW - In vivo KW - Ex vivo KW - Quantum yield KW - Dye KW - Quality assurance KW - Microscopy PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527843 DO - https://doi.org/10.3389/fonc.2021.654300 SN - 2234-943X VL - 11 SP - 1 EP - 8 PB - Frontiers Media CY - Lausanne AN - OPUS4-52784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaeger, Carsten A1 - Ritter, D. A1 - Goeritzer, M. A1 - Thiele, A. A1 - Blumrich, A. A1 - Beyhoff, N. A1 - Luettges, K. A1 - Smeir, E. A1 - Kasch, J. A1 - Grune, J. A1 - Müller, O. A1 - Klopfleisch, R. A1 - Foryst-Ludwig, A. A1 - Kintscher, U. T1 - Liver X Receptor Agonist AZ876 Induces Beneficial Endogenous Cardiac Lipid Reprogramming and Protects Against Isoproterenol-Induced Cardiac Damage N2 - Background - It is known that dietary intake of polyunsaturated fatty acids may improve cardiac function. However, relatively high daily doses are required to achieve sufficient cardiac concentrations of beneficial omega‐3 fatty acids. The liver X receptor (LXR) is a nuclear hormone receptor and a crucial regulator of lipid homeostasis in mammals. LXR activation has been shown to endogenously reprogram cellular lipid profiles toward increased polyunsaturated fatty acids levels. Here we studied whether LXR lipid reprogramming occurs in cardiac tissue and exerts cardioprotective actions. Methods and Results - Male 129SV mice were treated with the LXR agonist AZ876 (20 µmol/kg per day) for 11 days. From day 6, the mice were injected with the nonselective β‐agonist isoproterenol for 4 consecutive days to induce diastolic dysfunction and subendocardial fibrosis while maintaining systolic function. Treatment with isoproterenol led to a marked impairment of global longitudinal strain and the E/e' ratio of transmitral flow to mitral annular velocity, which were both significantly improved by the LXR agonist. Histological examination showed a significant reduction in isoproterenol‐induced subendocardial fibrosis by AZ876. Analysis of the cardiac lipid composition by liquid chromatography‐high resolution mass spectrometry revealed a significant increase in cardiac polyunsaturated fatty acids levels and a significant reduction in saturated fatty acids by AZ876. Conclusions - The present study provides evidence that the LXR agonist AZ876 prevents subendocardial damage, improves global longitudinal strain and E/e' in a mouse model of isoproterenol‐induced cardiac damage, accompanied by an upregulation of cardiac polyunsaturated fatty acids levels. Cardiac LXR activation and beneficial endogenous cardiac lipid reprogramming may provide a new therapeutic strategy in cardiac disease with diastolic dysfunction. KW - Heart failure KW - Lipids KW - Liver X receptor KW - Diastolic dysfunction KW - Nuclear receptor PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529352 DO - https://doi.org/10.1161/JAHA.120.019473 VL - 10 IS - 14 SP - e019473 AN - OPUS4-52935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Horf, M. A1 - Gebbers, R. A1 - Vogel, S. A1 - Ostermann, Markus A1 - Piepel, M.-F. A1 - Olfs, H.-W. T1 - Determination of Nutrients in Liquid Manures and Biogas Digestates by Portable Energy-Dispersive X-ray Fluorescence Spectrometry N2 - Knowing the exact nutrient composition of organic fertilizers is a prerequisite for their appropriate application to improve yield and to avoid environmental pollution by over-fertilization. Traditional standard chemical analysis is cost and time-consuming and thus it is unsuitable for a rapid analysis before manure application. As a possible alternative, a handheld X-ray fluorescence (XRF) spectrometer was tested to enable a fast, simultaneous, and on-site analysis of several elements. A set of 62 liquid pig and cattle manures as well as biogas digestates were collected, intensively homogenized and analysed for the macro plant nutrients phosphorus, potassium, magnesium, calcium, and sulphur as well as the micro nutrients manganese, iron, copper, and zinc using the standard lab procedure. The effect of four different sample preparation steps (original, dried, filtered, and dried filter residues) on XRF measurement accuracy was examined. Therefore, XRF results were correlated with values of the reference analysis. The best R2 s for each element ranged from 0.64 to 0.92. Comparing the four preparation steps, XRF results for dried samples showed good correlations (0.64 and 0.86) for all elements. XRF measurements using dried filter residues showed also good correlations with R2 s between 0.65 and 0.91 except for P, Mg, and Ca. In contrast, correlation Analysis for liquid samples (original and filtered) resulted in lower R2 s from 0.02 to 0.68, except for K (0.83 and 0.87, respectively). Based on these results, it can be concluded that handheld XRF is a promising measuring system for element analysis in manures and digestates. KW - XRF KW - Animal slurry KW - Fertilizer KW - Soil KW - Precision farming PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527622 DO - https://doi.org/10.3390/s21113892 VL - 21 IS - 11 SP - 3892 PB - MDPI CY - Basel, Switzerland AN - OPUS4-52762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoknecht, Ute A1 - Mathies, Helena A1 - Lisec, Jan T1 - Leaching and transformation of film preservatives in paints induced by combined exposure to ultraviolet radiation and water contact under controlled laboratory conditions N2 - Stormwater from urban areas can transport biocidally active substances and related transformation products from buildings into the environment. The occurrence of these substances in urban runoff depends on the availability of water, and on ultraviolet radiation exposure that causes photolytic reactions. In a systematic laboratory study, painted test specimens were exposed to either ultraviolet radiation, water contact, or a combination of both. Leaching of the biocidally active substances carbendazim, diuron, octylisothiazolinone, terbutryn, and selected transformation products of terbutryn and diuron were observed under various exposure conditions. Remaining concentrations of these substances in the paint were quantified. It was demonstrated that the distribution of active substances and transformation products in eluates and in the coatings themselves differs with exposure conditions. Strategies for environmental monitoring of biocide emissions need to consider the most relevant transformation products. However, environmental concentrations of biocidally active substances and transformation products depend on earlier exposure conditions. As a consequence, monitoring data cannot describe emission processes and predict expected leaching of biocidally active substances from buildings if the data are collected only occasionally. KW - Substance release KW - Construction products KW - Biocides KW - Transformation KW - UV radiation KW - Water contact PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532114 DO - https://doi.org/10.3390/w13172390 SN - 2073-4441 VL - 13 IS - 17 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-53211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munir, R. A1 - Lisec, Jan A1 - Jaeger, Carsten A1 - Zaidi, N. T1 - Abundance, fatty acid composition and saturation index of neutral lipids in colorectal cancer cell lines N2 - Lipid droplets, the dynamic organelles that store Triglycerides (TG) and cholesterol esters (CE), are highly accumulated in colon cancer cells. This work studies the TG and CE subspecies profile in colon carcinoma cell lines, SW480 derived from primary tumor, and SW620 derived from a metastasis of the same tumor. It was previously reported that the total TG and CE content is dramatically higher in SW620 cells; however, TG and CE subspecies profile has not been investigated in detail. The work presented here confirms that the total TG and CE Content is significantly higher in the SW620 cells. Moreover, the fatty acid (FA) composition of TG is significantly altered in the SW620 cells, with significant decrease in the abundance of saturated triglycerides. This resulted in a significantly decreased TG saturation index in the SW620 cells. The saturation index of CE was also significantly decreased in the SW620 cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533504 DO - https://doi.org/10.18388/abp.2020_5465 VL - 68 IS - 1 SP - 1 EP - 4 PB - ABP Acta Biochimica Polonica AN - OPUS4-53350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lisec, Jan A1 - Kobelt, D. A1 - Walther, W. A1 - Mokrizkij, M. A1 - Grötzinger, C. A1 - Jaeger, Carsten A1 - Baum, K. A1 - Simon, M. A1 - Wolf, J. A1 - Beindorf, N. A1 - Brenner, W. A1 - Stein, U. T1 - Systematic Identification of MACC1-Driven Metabolic Networks in Colorectal Cancer N2 - MACC1 is a prognostic and predictive metastasis biomarker for more than 20 solid Cancer entities. However, its role in cancer metabolism is not sufficiently explored. Here, we report on how MACC1 impacts the use of glucose, glutamine, lactate, pyruvate and fatty acids and show the comprehensive analysis of MACC1-driven metabolic networks. We analyzed concentrationdependent changes in nutrient use, nutrient depletion, metabolic tracing employing 13C-labeled substrates, and in vivo studies. We found that MACC1 permits numerous effects on cancer metabolism. Most of those effects increased nutrient uptake. Furthermore, MACC1 alters metabolic pathways by affecting metabolite production or turnover from metabolic substrates. MACC1 supports use of glucose, glutamine and pyruvate via their increased depletion or altered distribution within metabolic pathways. In summary, we demonstrate that MACC1 is an important regulator of metabolism in cancer cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533526 DO - https://doi.org/10.3390/cancers13050978 VL - 13 IS - 5 SP - 1 EP - 22 PB - MDPI Journal Cancers AN - OPUS4-53352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adamus, A. A1 - Ali, I. A1 - Vasileiadis, V. A1 - Al-Hileh, L. A1 - Lisec, Jan A1 - Frank, M. A1 - Seitz, G. A1 - Engel, N. T1 - Vincetoxicum arnottianum modulates motility features and metastatic marker expression in pediatric rhabdomyosarcoma by stabilizing the actin cytoskeleton N2 - Background: Prevention of metastatic invasion is one of the main challenges in the treatment of alveolar rhabdomyosarcoma. Still the therapeutic options are limited. Therefore, an anti-tumor screening was initiated focusing on the anti-metastatic and anti-invasion properties of selected medicinal plant extracts and phytoestrogens, already known to be effective in the prevention and treatment of different cancer entities. Methods: Treatment effects were first evaluated by cell viability, migration, invasion, and colony forming assays on the alveolar rhabdomyosarcoma cell line RH-30 in comparison with healthy primary cells. Results: Initial anti-tumor screenings of all substances analyzed in this study, identified the plant extract of Vincetoxicum arnottianum (VSM) as the most promising candidate, harboring the highest anti-metastatic potential. Those significant anti-motility properties were proven by a reduced ability for migration (60%), invasion (99%) and colony formation (61%) under 48 h exposure to 25 μg/ml VSM. The restricted motility features were due to an induction of the stabilization of the cytoskeleton – actin fibers were 2.5-fold longer and were spanning the entire cell. Decreased proliferation (PCNA, AMT, GCSH) and altered metastasis (e. g. SGPL1, CXCR4, stathmin) marker expression on transcript and protein level confirmed the significant lowered tumorigenicity under VSM treatment. Finally, significant alterations in the cell metabolism were detected for 25 metabolites, with levels of uracil, N-acetyl serine and propanoyl phosphate harboring the greatest alterations. Compared to the conventional therapy with cisplatin, VSM treated cells demonstrated a similar metabolic shutdown of the primary cell metabolism. Primary control cells were not affected by the VSM treatment. Conclusions: This study revealed the VSM root extract as a potential, new migrastatic drug candidate for the putative treatment of pediatric alveolar rhabdomyosarcoma with actin filament stabilizing properties and accompanied by a marginal effect on the vitality of primary cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533530 DO - https://doi.org/10.1186/s12906-021-03299-x VL - 21 IS - 1 PB - Springer Nature AN - OPUS4-53353 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geißler, Daniel A1 - Nirmalananthan-Budau, Nithiya A1 - Scholtz, Lena A1 - Tavernaro, Isabella A1 - Resch-Genger, Ute T1 - Analyzing the surface of functional nanomaterials — how to quantify the total and derivatizable number of functional groups and ligands N2 - Functional nanomaterials (NM) of different size, shape, chemical composition, and surface chemistry are of increasing relevance for many key technologies of the twenty-first century. This includes polymer and silica or silica-coated nanoparticles (NP) with covalently bound surface groups, semiconductor quantum dots (QD), metal and metal oxide NP, and lanthanide-based NP with coordinatively or electrostatically bound ligands, as well as surface-coated nanostructures like micellar encapsulated NP. The surface chemistry can significantly affect the physicochemical properties of NM, their charge, their processability and performance, as well as their impact on human health and the environment. Thus, analytical methods for the characterization of NM surface chemistry regarding chemical identification, quantification, and accessibility of functional groups (FG) and surface ligands bearing such FG are of increasing importance for quality control of NM synthesis up to nanosafety. Here, we provide an overview of analytical methods for FG analysis and quantification with special emphasis on bioanalytically relevant FG broadly utilized for the covalent attachment of biomolecules like proteins, peptides, and oligonucleotides and address methodand material-related challenges and limitations. Analytical techniques reviewed include electrochemical titration methods, optical assays, nuclear magnetic resonance and vibrational spectroscopy, as well as X-ray based and thermal analysis methods, covering the last 5–10 years. Criteria for method classification and evaluation include the need for a signal-generating label, provision of either the total or derivatizable number of FG, need for expensive instrumentation, and suitability for process and production control during NM synthesis and functionalization. KW - Functional group quantification KW - Surface ligand KW - Nanomaterial KW - Optical detection KW - Electrochemical titration KW - Nanosafety (Safe-by-design) PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533597 DO - https://doi.org/10.1007/s00604-021-04960-5 VL - 188 IS - 10 SP - 1 EP - 28 PB - Springer Nature AN - OPUS4-53359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dariz, P. A1 - Schmid, Thomas T1 - Raman focal point on Roman Egyptian blue elucidates disordered cuprorivaite, green glass phase and trace compounds N2 - The discussed comparative analyses of Roman Imperial pigment balls and fragmentary murals unearthed in the ancient cities of Aventicum and Augusta Raurica (Switzerland) by means of Raman microspectroscopy pertain to a predecessor study on trace compounds in Early Medieval Egyptian blue (St. Peter, Gratsch, South Tyrol, Northern Italy). The plethora of newly detected associated minerals of the raw materials surviving the synthesis procedure validate the use of quartz sand matching the composition of sediments transported by the Volturno river into the Gulf of Gaeta (Campania, Southern Italy) with a roasted sulphidic copper ore and a mixed-alkaline plant ash as fluxing agent. Thus, the results corroborate a monopolised pigment production site located in the northern Phlegrean Fields persisting over the first centuries A.D., this in line with statements of the antique Roman writers Vitruvius and Pliny the Elder and recent archaeological evidences. Beyond that, Raman spectra reveal through gradual peak shifts and changes of band width locally divergent process conditions and compositional inhomogeneities provoking crystal lattice disorder in the chromophoric cuprorivaite as well as the formation of a copper-bearing green glass phase, the latter probably in dependency of the concentration of alkali flux, notwithstanding that otherwise solid-state reactions predominate the synthesis. KW - Raman microspectroscopy KW - Egyptian blue KW - Cuprorivaite PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559028 DO - https://doi.org/10.1038/s41598-022-19923-w SN - 2045-2322 VL - 12 IS - 1 SP - 1 EP - 12 PB - Nature Publishing Group CY - London AN - OPUS4-55902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Wan, Wei A1 - Rurack, Knut T1 - Toward Label-Free Optical Multiplexing of Analytes in Indicator Release Lateral Flow Assays via Detection Zones Containing Tailored Capture Materials N2 - The use of macromolecules and materials immobilized in the detection zone of test strips for indicator capture and focusing in label-free lateral flow assays (LFAs) is described, with emphasis on its future use in low number multiplexing. Several materials such as polyelectrolytes, functionalized mesoporous silica micro- and nanoparticles, chemically modified cellulose or glass fibre (GF) membranes and molecularly imprinted polymer gels coated onto membranes were studied in model assays, before the most promising materials were combined with antibody-gated indicator delivering (gAID) sensor materials. Cellulose, nitrocellulose and GF membranes were used as supports and highly fluorescent dyes of different charge states as model indicators. Combination of the best performing capture materials with gAID systems made it possible to distinctly increase the sensitivity and reduce the measurement uncertainty in the LFA testing of pentaerythritol tetranitrate (PETN) in aqueous samples. In addition, dual-plexing of PETN and 2,4,6-trinitrotoluene (TNT) was realized on a single test strip containing two dedicated capture zones. KW - Rapid tests KW - Vor-Ort-Analytik KW - Multiplexing KW - Teststreifen KW - Molecularly imprinted polymers PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557873 DO - https://doi.org/10.1002/anse.202100062 VL - 2 IS - 4 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-55787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Bliesener, Lilly A1 - Weiss, Tilman A1 - Koch, Matthias T1 - Marker Substances in the Aroma of Truffles N2 - The aim of this study was to identify specific truffle marker substances within the truffle aroma. The aroma profile of different truffle species was analyzed using static headspace sampling with gas chromatography mass spectrometry analysis (SHS/GC-MS). Possible marker substances were identified, taking the additional literature into account. The selected marker substances were tested in an experiment with 19 truffle dogs. The hypothesis “If trained truffle dogs recognize the substances as supposed truffles in the context of an experiment, they can be regarded as specific” was made. As it would be nearly impossible to investigate every other possible emitter of the same compounds to determine their specificity, this hypothesis was a reasonable approximation. We were interested in the question of what it is the dogs actually search for on a chemical level and whether we can link their ability to find truffles to one or more specific marker substances. The results of the dog experiment are not as unambiguous as could have been expected based on the SHS/GC-MS measurements. Presumably, the truffle aroma is mainly characterized and perceived by dogs by dimethyl sulfide and dimethyl disulfide. However, as dogs are living beings and not analytical instruments, it seems unavoidable that one must live with some degree of uncertainty regarding these results. KW - Truffle KW - Volatile organic compounds; KW - Gas chromatography KW - Mass spectrometry KW - Canine olfactometry PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556116 DO - https://doi.org/10.3390/molecules27165169 SN - 1420-3049 VL - 27 IS - 16 SP - 1 EP - 19 PB - MDPI CY - Basel AN - OPUS4-55611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spallanzani, Roberta A1 - Koga, K. A1 - Cichy, S. A1 - Wiedenbeck, M. A1 - Schmidt, B. A1 - Oelze, Marcus A1 - Wilke, M. T1 - Lithium and boron difusivity and isotopic fractionation in hydrated rhyolitic melts N2 - Lithium and boron are trace components of magmas, released during exsolution of a gas phase during volcanic activity. In this study, we determine the difusivity and isotopic fractionation of Li and B in hydrous silicate melts. Two glasses were synthesized with the same rhyolitic composition (4.2 wt% water), having diferent Li and B contents; these were studied in difusion-couple experiments that were performed using an internally heated pressure vessel, operated at 300 MPa in the temperature range 700–1250 °C for durations from 0 s to 24 h. From this we determined activation energies for Li and B difusion of 57±4 kJ/mol and 152±15 kJ/mol with pre-exponential factors of 1.53 × 10–7 m2/s and 3.80× 10–8 m2 /s, respectively. Lithium isotopic fractionation during difusion gave β values between 0.15 and 0.20, whereas B showed no clear isotopic fractionation. Our Li difusivities and isotopic fractionation results difer somewhat from earlier published values, but overall confrm that Li difusivity increases with water content. Our results on B difusion show that similarly to Li, B mobility increases in the presence of water. By applying the Eyring relation, we confrm that B difusivity is limited by viscous fow in silicate melts. Our results on Li and B difusion present a new tool for understanding degassing-related processes, ofering a potential geospeedometer to measure volcanic ascent rates. KW - Hydrated silicate melts KW - Stable isotopes KW - Diffusion KW - Isotopic fractionation PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554496 DO - https://doi.org/10.1007/s00410-022-01937-2 VL - 177 IS - 8 SP - 1 EP - 17 PB - Springer AN - OPUS4-55449 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Golusda, L. A1 - Kühl, A. A. A1 - Lehmann, M. A1 - Dahlke, K. A1 - Mueller, S. A1 - Boehm-Sturm, P. A1 - Saatz, Jessica A1 - Traub, Heike A1 - Schnorr, J. A1 - Freise, C. A1 - Taupitz, M. A1 - Biskup, K. A1 - Blanchard, V. A1 - Klein, O. A1 - Sack, I. A1 - Siegmund, B. A1 - Paclik, D. T1 - Visualization of inflammation in experimental colitis by magnetic resonance imaging using very small superparamagnetic iron oxide particles N2 - Inflammatory bowel diseases (IBD) comprise mainly ulcerative colitis (UC) and Crohn´s disease (CD). Both forms present with a chronic inflammation of the (gastro) intestinal tract, which induces excessive changes in the composition of the associated extracellular matrix (ECM). In UC, the inflammation is limited to the colon, whereas it can occur throughout the entire gastrointestinal tract in CD. Tools for early diagnosis of IBD are still very limited and highly invasive and measures for standardized evaluation of structural changes are scarce. To investigate an efficient non-invasive way of diagnosing intestinal inflammation and early changes of the ECM, very small superparamagnetic iron oxide nanoparticles (VSOPs) in magnetic resonance imaging (MRI) were applied in two mouse models of experimental colitis: the dextran sulfate sodium (DSS)-induced colitis and the transfer model of colitis. For further validation of ECM changes and inflammation, tissue sections were analyzed by immunohistochemistry. For in depth ex-vivo investigation of VSOPs localization within the tissue, Europium-doped VSOPs served to visualize the contrast agent by imaging mass cytometry (IMC). VSOPs accumulation in the inflamed colon wall of DSS-induced colitis mice was visualized in T2* weighted MRI scans. Components of the ECM, especially the hyaluronic acid content, were found to influence VSOPs binding. Using IMC, colocalization of VSOPs with macrophages and endothelial cells in colon tissue was shown. In contrast to the DSS model, colonic inflammation could not be visualized with VSOP-enhanced MRI in transfer colitis. VSOPs present a potential contrast agent for contrast-enhanced MRI to detect intestinal inflammation in mice at an early stage and in a less invasive manner depending on hyaluronic acid content. KW - Inflammation KW - Imaging KW - Immunohistochemistry KW - MRI KW - Nanoparticle KW - Extracellular matrix KW - Laser ablation KW - ICP-MS PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555395 DO - https://doi.org/10.3389/fphys.2022.862212 SN - 1664-042X VL - 13 IS - July 2022 SP - 1 EP - 15 PB - Frontiers Research Foundation CY - Lausanne AN - OPUS4-55539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kimani, Martha Wamaitha A1 - Kislenko, Evgeniia A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Fluorescent molecularly imprinted polymer particles for glyphosate detection using phase transfer agents N2 - In this work, molecular imprinting was combined with direct fluorescence detection of the pesticide Glyphosate (GPS). Firstly, the solubility of highly polar GPS in organic solvents was improved by using lipophilic tetrabutylammonium (TBA+) and tetrahexylammonium (THA+) counterions. Secondly, to achieve fluorescence detection, a fluorescent crosslinker containing urea-binding motifs was used as a probe for GPS-TBA and GPS-THA salts in chloroform, generating stable complexes through hydrogen bond formation. The GPS/fluorescent dye complexes were imprinted into 2–3 nm fluorescent molecularly imprinted polymer (MIP) shells on the surface of sub-micron silica particles using chloroform as porogen. Thus, the MIP binding behavior could be easily evaluated by fluorescence titrations in suspension to monitor the spectral changes upon addition of the GPS analytes. While MIPs prepared with GPS-TBA and GPS-THA both displayed satisfactory imprinting following titration with the corresponding analytes in chloroform, GPS-THA MIPs displayed better selectivity against competing molecules. Moreover, the THA+ counterion was found to be a more powerful phase transfer agent than TBA+ in a biphasic assay, enabling the direct fluorescence detection and quantification of GPS in water. A limit of detection of 1.45 μM and a linear range of 5–55 μM were obtained, which match well with WHO guidelines for the acceptable daily intake of GPS in water (5.32 μM). KW - Glyphosate KW - Molecular imprinting KW - Core-shell particles KW - Fluorescent sensors PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555281 DO - https://doi.org/10.1038/s41598-022-16825-9 SN - 2045-2322 VL - 12 IS - 1 SP - 1 EP - 15 PB - Macmillan Publishers Limited CY - London AN - OPUS4-55528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Orf, I. A1 - Tenenboim, H. A1 - Omranian, N. A1 - Nikoloski, Z. A1 - Fernie, A. R. A1 - Lisec, Jan A1 - Brotman, Y. A1 - Bromke, M. A. T1 - Transcriptomic and Metabolomic Analysis of a Pseudomonas-Resistant versus a Susceptible Arabidopsis Accession N2 - Accessions of one plant species may show significantly different levels of susceptibility to stresses. The Arabidopsis thaliana accessions Col-0 and C24 differ significantly in their resistance to the pathogen Pseudomonas syringae pv. tomato (Pst). To help unravel the underlying mechanisms contributing to this naturally occurring variance in resistance to Pst, we analyzed changes in transcripts and compounds from primary and secondary metabolism of Col-0 and C24 at different time points after infection with Pst. Our results show that the differences in the resistance of Col-0 and C24 mainly involve mechanisms of salicylic-acid-dependent systemic acquired resistance, while responses of jasmonic-acid-dependent mechanisms are shared between the two accessions. In addition, arginine metabolism and differential activity of the biosynthesis pathways of aliphatic glucosinolates and indole glucosinolates may also contribute to the resistance. Thus, this study highlights the difference in the defense response strategies utilized by different genotypes. KW - Mass Spectrometry KW - Arabidopsis KW - Resistance PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559549 DO - https://doi.org/10.3390/ijms232012087 VL - 23 IS - 20 SP - 1 EP - 27 PB - MDPI AN - OPUS4-55954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Mauch, Tatjana A1 - Riedel, Juliane T1 - Development of a Hydrazine-Based Solid-Phase Extraction and Clean-Up Method for Highly Selective Quantification of Zearalenone in Edible Vegetable Oils by HPLC-FLD N2 - Rapid, cost-efficient, and eco-friendly methods are desired today for routine analysis of the Fusarium mycotoxin zearalenone (ZEN) in edible vegetable oils. Liquid chromatography with fluorescence detection (HPLC-FLD) is commonly used to reliably control the specified ZEN maximum levels, which requires efficient sample clean-up to avoid matrix interferences. Therefore, a highly selective extraction and clean-up method based on reversible covalent hydrazine chemistry (RCHC) using hydrazine-functionalized silica was developed. This efficient solid-phase extraction (SPE) involves reversible hydrazone formation of ZEN with the hydrazine moiety covalently bound to a solid phase. Optimal conditions were achieved with 1 mL SPE cartridges filled with 400 mg of hydrazine-functionalized silica. The developed RCHC-SPE method was validated in an interlaboratory comparison study (ILC) with twelve participants analyzing six edible vegetable oils with a focus on maize oils. The derived method parameters (ZEN recovery 83%, repeatability 7.0%, and reproducibility 18%) meet the performance criteria of Commission Regulation (EC) No 401/2006. The developed RCHC-SPE-based HPLC-FLD method allows the reliable quantification of ZEN in the range of 47–494 μg/kg for different types of edible vegetable oils, also for matrix-reach native oils. Due to the high efficiency, the significantly reduced matrix load helps to extend the lifetime of analytical equipment. Furthermore, the re-useability of the RCHC-SPE cartridges contributes to an eco-friendly approach and reduced analysis costs. To our knowledge, this is the first report on ZEN quantification in edible vegetable oils based on manual RCHC-SPE cartridges. Due to its high performance, the developed RCHC-SPE method is a promising alternative to the current European standard method EN 16924:2017 (HPLC-FLD part). KW - Mycotoxin KW - Food KW - Reversible covalent hydrazine chemistry (RCHC) KW - Quantitative determination PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554812 DO - https://doi.org/10.3390/toxins14080549 VL - 14 IS - 8 PB - MDPI CY - Basel AN - OPUS4-55481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knoche, Lisa A1 - Lisec, Jan A1 - Koch, Matthias T1 - Analysis of electrochemical and liver microsomal transformation products of lasalocid by LC/HRMS N2 - Rationale: Lasalocid (LAS), an ionophore, is used in cattle and poultry farming as feed additive for its antibiotic and growth-promoting properties. Literature on transformation products (TP) resulting from LAS degradation is limited. So far, only hydroxylation is found to occur as the metabolic reaction during the LAS degradation. To investigate potential TPs of LAS, we used electrochemistry (EC) and liver microsome (LM) assays to synthesize TPs, which were identified using liquid chromatography high-resolution mass spectrometry (LC/HRMS). Methods: Electrochemically produced TPs were analyzed online by direct coupling of the electrochemical cell to the electrospray ionization (ESI) source of a Sciex Triple-TOF high resolution mass spectrometer. Then, EC-treated LAS solution was collected and analyzed offline using LC/HRMS to confirm stable TPs and improve their annotation with a chemical structure due to informative MS/MS spectra. In a complementary approach, TPs formed by rat and human microsomal incubation were investigated using LC/HRMS. The resulting data were used to investigate LAS modification reactions and elucidate the chemical structure of obtained TPs. Results: The online measurements identified a broad variety of TPs, resulting from modification reactions like (de-)hydrogenation, hydration, methylation, oxidation as well as adduct formation with methanol. We consistently observed different ion complexations of LAS and LAS-TPs (Na+; 2Na+ K+; NaNH4 +; KNH4 +). Two stable methylated EC-TPs were found, structurally annotated, and assigned to a likely modification reaction. Using LM incubation, seven TPs were formed, mostly by oxidation/hydroxylation. After the identification of LM-TPs as Na+-complexes, we identified LM-TPs as K+-complexes. Conclusion: We identified and characterized TPs of LAS using EC- and LM-based methods. Moreover, we found different ion complexes of LAS-based TPs. This knowledge, especially the different ion complexes, may help elucidate the metabolic and environmental degradation pathways of LAS. KW - Mass Spectrometry KW - Electrochemistry KW - ECR KW - Lasalocid KW - Ionophore KW - Transformation products PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553919 DO - https://doi.org/10.1002/rcm.9349 VL - 36 IS - 18 SP - 1 EP - 10 PB - Wiley online library AN - OPUS4-55391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gornushkin, Igor B. A1 - Völker, Tobias T1 - Intrinsic Performance of Monte Carlo Calibration-Free Algorithm for Laser-Induced Breakdown Spectroscopy N2 - The performance of the Monte Carlo (MC) algorithm for calibration-free LIBS was studied on the example of a simulated spectrum that mimics a metallurgical slag sample. The underlying model is that of a uniform, isothermal, and stationary plasma in local thermodynamical equilibrium. Based on the model, the algorithm generates from hundreds of thousands to several millions of simultaneous configurations of plasma parameters and the corresponding number of spectra. The parameters are temperature, plasma size, and concentrations of species. They are iterated until a cost function, which indicates a difference between synthetic and simulated slag spectra, reaches its minimum. After finding the minimum, the concentrations of species are read from the model and compared to the certified values. The algorithm is parallelized on a graphical processing unit (GPU) to reduce computational time. The minimization of the cost function takes several minutes on the GPU NVIDIA Tesla K40 card and depends on the number of elements to be iterated. The intrinsic accuracy of the MC calibration-free method is found to be around 1% for the eight elements tested. For a real experimental spectrum, however, the efficiency may turn out to be worse due to the idealistic nature of the model, as well as incorrectly chosen experimental conditions. Factors influencing the performance of the method are discussed. KW - Laser induced breakdown spectroscopy KW - Calibration-free analysis KW - Monte Carlo algorithm PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558016 DO - https://doi.org/10.3390/s22197149 VL - 22 IS - 19 SP - 7149 PB - MDPI AN - OPUS4-55801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Tobias A1 - Gornushkin, Igor B. T1 - Importance of physical units in the Boltzmann plot method N2 - The Boltzmann plot is one of the most widely used methods for determining the temperature in different types of laboratory plasmas. It operates on the logarithm as a function of the dimensional argument, which assumes that the correct physical units are used. In many works using the Boltzmann method, there is no analysis of the dimension of this argument, which may be the cause of a potential error. This technical note offers a brief description of the method and shows how to correctly use physical units when using transcendental functions like the logarithm. KW - Boltzmann plot KW - Laser induced plasma PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558039 DO - https://doi.org/10.1039/d2ja00241h SP - 1 EP - 3 PB - Royal Society of Chemistry AN - OPUS4-55803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sichler, Theresa Constanze A1 - Adam, Christian A1 - Barjenbruch, M. A1 - Montag, D. A1 - Mauch, Tatjana A1 - Sommerfeld, Thomas A1 - Ehm, J.H. T1 - Variation of the element composition of municipal sewage sludges in the context of new regulations on phosphorus recovery in Germany N2 - Phosphorus (P) recovery is obligatory for all sewage sludges with more than 20 g P/kg dry matter (DM) from 2029 in Germany. Nine wastewater treatment plants (WWTPs) were chosen to investigate variations of phosphorus contents and other parameters in sewage sludge over the year. Monthly sewage sludge samples from each WWTP were analyzed for phosphorus and other matrix elements (C, N, H, Ca, Fe, Al, etc.), for several trace elements (As, Cr, Mo, Ni, Pb, Sn) and loss of ignition. Among the nine WWTPs, there are four which have phosphorus contents both above and below the recovery limit of 20 g/kg DM along the year. Considering the average phosphorus content over the year, only one of them is below the limit. Compared to other matrix elements and parameters, phosphorus fuctuations are low with an average of 7% over all nine WWTPs. In total, only hydrogen and carbon are more constant in the sludge. In several WWTPs with chemical phosphorus elimination, phosphorus fuctuations showed similar courses like iron and/or aluminum. WWTPs with chamber flter presses rather showed dilution efects of calcium dosage. As result of this study, monthly phosphorus measurement is highly recommended to determine whether a WWTP is below the 20 g/kg DM limit. KW - Sewage sludge KW - Phosphorus recovery KW - Wastewater KW - Phosphorus elimination PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557499 DO - https://doi.org/10.1186/s12302-022-00658-4 SN - 2190-4707 VL - 34 IS - 1 SP - 1 EP - 12 PB - Springer Nature CY - Berlin AN - OPUS4-55749 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stein, L. A1 - Wang, Cui A1 - Förster, C. A1 - Resch-Genger, Ute A1 - Heinze, K. T1 - Bulky ligands protect molecular ruby from oxygen quenching N2 - Chromium(III) complexes can show phosphorescence from the spin-flip excited doublet states 2E/2T1 in the near-infrared with high photoluminescence quantum yields and extremely long lifetimes in the absence of dioxygen. The prototype molecular ruby, [Cr(ddpd)2]3+ (ddpd = N,N’-dimethyl-N,N’-dipyridine-2-ylpyridine-2,6-diamine), has a photoluminescence quantum yield and a luminescence lifetime of 13.7% and 1.1 ms in deaerated acetonitrile, respectively. However, its luminescence is strongly quenched by 3O2 via an efficient Dexter-type energy transfer process. To enable luminescence applications of molecular rubies in solution under aerobic conditions, we explored the potential of sterically demanding ddpd ligands to shield the chromium(III) center from O2 using steady state and time-resolved photoluminescence spectroscopy. The structures of the novel complexes with sterically demanding ligands were investigated by single crystal X-ray diffraction and quantum chemically by density functional theory calculations. The O2 sensitivity of the photoluminescence was derived from absolutely measured photoluminescence quantum yields and excited state lifetimes under inert and aerobic conditions and by Stern–Volmer analyses of these data. Optimal sterically shielded chromium(III) complexes revealed photoluminescence quantum yields of up to 5.1% and excited state lifetimes of 518 μs in air-saturated acetonitrile, underlining the large potential of this ligand design approach to broaden the applicability of highly emissive chromium(III) complexes. KW - Fluorescence KW - Synthesis KW - Production KW - Optical spectroscopy KW - Ligand KW - Photophysics KW - Cr(III) KW - Mechanism KW - NIR KW - Sensor KW - Oxygen PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570807 DO - https://doi.org/10.1039/d2dt02950b VL - 51 IS - 46 SP - 17664 EP - 17670 PB - The Royal Society of Chemistry CY - Berlin AN - OPUS4-57080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Koch, Matthias T1 - On-Site Detection of Volatile Organic Compounds (VOCs) N2 - Volatile organic compounds (VOCs) are of interest in many different fields. Among them are food and fragrance analysis, environmental and atmospheric research, industrial applications, security or medical and life science. In the past, the characterization of these compounds was mostly performed via sample collection and off-site analysis with gas chromatography coupled to mass spectrometry (GC-MS) as the gold standard. While powerful, this method also has several drawbacks such as being slow, expensive, and demanding on the user. For decades, intense research has been dedicated to find methods for fast VOC analysis on-site with time and spatial resolution. We present the working principles of the most important, utilized, and researched technologies for this purpose and highlight important publications from the last five years. In this overview, non-selective gas sensors, electronic noses, spectroscopic methods, miniaturized gas chromatography, ion mobility spectrometry and direct injection mass spectrometry are covered. The advantages and limitations of the different methods are compared. Finally, we give our outlook into the future progression of this field of research. KW - Volatile organic compounds KW - On-site detection KW - Mobile analytics KW - Sensors PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570885 DO - https://doi.org/10.3390/molecules28041598 VL - 28 IS - 4 SP - 1 EP - 19 PB - MDPI CY - Basel, Switzerland AN - OPUS4-57088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Borzekowski, Antje A1 - Drewitz, T. A1 - Keller, Julia A1 - Pfeifer, Dietmar A1 - Kunte, Hans-Jörg A1 - Koch, Matthias A1 - Rohn, S. A1 - Maul, R. T1 - Biosynthesis and characterization of zearalenone-14-sulfate, zearalenone-14-glucoside and zearalenone-16-glucoside using common fungal strains N2 - Zearalenone (ZEN) and its phase II sulfate and glucoside metabolites have been detected in food and feed commodities. After consumption, the conjugates can be hydrolyzed by the human intestinal microbiota leading to liberation of ZEN that implies an underestimation of the true ZEN exposure. To include ZEN conjugates in routine analysis, reliable standards are needed, which are currently not available. Thus, the aim of the present study was to develop a facilitated biosynthesis of ZEN-14-sulfate, ZEN-14-glucoside and ZEN-16-glucoside. A metabolite screening was conducted by adding ZEN to liquid fungi cultures of known ZEN conjugating Aspergillus and Rhizopus strains. Cultivation conditions and ZEN incubation time were varied. All media samples were analyzed for metabolite formation by HPLC-MS/MS. In addition, a consecutive biosynthesis was developed by using Fusarium graminearum for ZEN biosynthesis with subsequent conjugation of the toxin by utilizing Aspergillus and Rhizopus species. ZEN-14-sulfate (yield: 49%) is exclusively formed by Aspergillus oryzae. ZEN-14-glucoside (yield: 67%) and ZEN-16-glucoside (yield: 39%) are formed by Rhizopus oryzae and Rhizopus oligosporus, respectively. Purities of ≥73% ZEN-14-sulfate, ≥82% ZEN-14-glucoside and ≥50% ZEN-16-glucoside were obtained by 1H-NMR. In total, under optimized cultivation conditions, fungi can be easily utilized for a targeted and regioselective synthesis of ZEN conjugates. KW - Mycotoxin KW - Zearalenone KW - Conjugate KW - Biosynthesis KW - Fusarium KW - Aspergillus KW - Rhizopus PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-444246 DO - https://doi.org/10.3390/toxins10030104 SN - 2072-6651 VL - 10 IS - 3 SP - Article 104, 1 EP - 15 PB - MDPI CY - Basel AN - OPUS4-44424 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bell, Jérémy A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Die 3D-Mikrofluidik mit molekular geprägten Polymerpartikeln eröffnet neue Möglichkeiten der selektiven Pestizid-Bestimmung in Wasser N2 - 2,4-D ist ein in der Landwirtschaft weitverbreitetes Pflanzenschutzmittel, das Grundwasser kontaminiert, sich innerhalb der Nahrungskette anreichert und Umwelt- und Gesundheitsprobleme verursachen kann. Hier stellen die Autoren ein mikrofluidisches Nachweissystem für die Echtzeitdetektion von 2,4-D in Grund- oder Oberflächenwasser vor. Es basiert auf der Kombination 2,4-D-selektiver, fluoreszierender, molekular geprägter Polymer-(MIP-)Mikropartikel mit einem 3D-mikrofluidischen Extraktions- und Detektionssystem. Messungen vor Ort sollen damit künftig möglich sein. KW - 3D-Mikrofluidik KW - Sensorpartikel KW - MIP KW - Pestizid PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-444781 UR - https://www.labo.de/epaper/LA0318/index.html SN - 0344-5208 IS - 3 SP - 10 EP - 13 PB - WEKA Business Medien GmbH AN - OPUS4-44478 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Laux, P. A1 - Tentschert, J. A1 - Riebeling, Ch. A1 - Braeuning, A. A1 - Creutzenberg, O. A1 - Epp, A. A1 - Fessard, V. A1 - Haas, K.-H. A1 - Haase, A. A1 - Hund-Rinke, K. A1 - Jakubowski, Norbert A1 - Kearns, P. A1 - Lampen, A. A1 - Rauscher, H. A1 - Schoonjans, R. A1 - Störmer, A. A1 - Thielmann, A. A1 - Mühle, U. A1 - Luch, A. T1 - Nanomaterials: certain aspects of application, risk assessment and risk communication N2 - Development and market introduction of new nanomaterials trigger the need for an adequate risk assessment of such products alongside suitable risk communication measures. Current application of classical and new nanomaterials is analyzed in context of regulatory requirements and standardization for chemicals, food and consumer products. The challenges of nanomaterial characterization as the main bottleneck of risk assessment and regulation are presented. In some areas, e.g., quantification of nanomaterials within complex matrices, the establishment and adaptation of analytical techniques such as laser ablation inductively coupled plasma mass spectrometry and others are potentially suited to meet the requirements. As an example, we here provide an approach for the reliable characterization of human exposure to nanomaterials resulting from food packaging. Furthermore, results of nanomaterial toxicity and ecotoxicity testing are discussed, with concluding key criteria such as solubility and fiber rigidity as important parameters to be considered in material development and regulation. Although an analysis of the public opinion has revealed a distinguished rating depending on the particular field of application, a rather positive perception of nanotechnology could be ascertained for the German public in general. An improvement of material characterization in both toxicological testing as well as end-product control was concluded as being the main obstacle to ensure not only safe use of materials, but also wide acceptance of this and any novel technology in the general public. KW - Nanomaterials KW - Toxicity KW - Ecotoxicity KW - Standardization KW - Exposure PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-441096 DO - https://doi.org/10.1007/s00204-017-2144-1 VL - 92 IS - 1 SP - 121 EP - 141 PB - Springer AN - OPUS4-44109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer, S. A1 - López-Serrano, Ana A1 - Mitze, H. A1 - Jakubowski, Norbert A1 - Schwerdtle, T. T1 - Single-cell analysis by ICP-MS/MS as a fast tool for cellular bioavailability studies of arsenite N2 - Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) has become a powerful and fast tool to evaluate the elemental composition at a single-cell level. In this study, the cellular bioavailability of arsenite (incubation of 25 and 50 μM for 0-48 h) has been successfully assessed by SC-ICP-MS/MS for the first time directly after re-suspending the cells in water. This procedure avoids the normally arising cell membrane permeabilization caused by cell fixation methods (e.g. methanol fixation). The reliability and feasibility of this SC-ICP-MS/MS approach with a limit of detection of 0.35 fg per cell was validated by conventional bulk ICP-MS/MS analysis after cell digestion and parallel measurement of sulfur and phosphorus. KW - Single-cell analysis KW - ICP-MS/MS KW - Arsenite PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-441105 DO - https://doi.org/10.1039/c7mt00285h SN - 1756-5901 VL - 10 IS - 1 SP - 73 EP - 76 PB - RSC Publ. CY - Cambridge AN - OPUS4-44110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keller, Julia A1 - Borzekowski, Antje A1 - Haase, H. A1 - Menzel, R. A1 - Rueß, L. A1 - Koch, Matthias T1 - Toxicity assay for citrinin, zearalenone and zearalenone-14-sulfate using the nematode Caenorhabditis elegans as model organism N2 - To keep pace with the rising number of detected mycotoxins, there is a growing need for fast and reliable toxicity tests to assess the potential threat to food safety. Toxicity tests with the bacterial-feeding nematode Caenorhabditis elegans as model organism are well established. In this study the C. elegans wildtype strain N2 (var. Bristol) was used to investigate the toxic effects of the food-relevant mycotoxins citrinin (CIT) and zearalenone-14-sulfate (ZEA-14-S) and zearalenone (ZEA) on different life cycle parameters including reproduction, thermal and oxidative stress resistance and lifespan. The metabolization of the mycotoxins by the nematodes in vivo was investigated using HPLC-MS/MS. ZEA was metabolized in vivo to the reduced isomers α-zearalenol (α-ZEL) and β-ZEL. ZEA 14-S was reduced to α-/β-ZEL 14-sulfate and CIT was metabolized to mono-hydroxylated CIT. All mycotoxins tested led to a significant decrease in the number of nematode offspring produced. ZEA and CIT displayed negative effects on stress tolerance levels and for CIT an additional shortening of the mean lifespan was observed. In the case of ZEA-14-S, however, the mean lifespan was prolonged. The presented study shows the applicability of C. elegans for toxicity testing of emerging food mycotoxins for the purpose of assigning potential health threats. KW - Mycotoxins KW - Metabolization KW - Toxicity testing KW - Biotests PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-455772 DO - https://doi.org/10.3390/toxins10070284 VL - 10 IS - 7 SP - 284, 1 EP - 12 PB - MDPI AN - OPUS4-45577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weber, A. A1 - von Randow, M. A1 - Voigt, A.-L. A1 - von der Au, Marcus A1 - Fischer, E. A1 - Meermann, Björn A1 - Wagner, M. T1 - Ingestion and toxicity of microplastics in the freshwater gastropodLymnaea stagnalis: No microplastic-induced effects alone or incombination with copper N2 - The interaction of microplastics with freshwater biota and their interaction with other stressors is still not very well understood. Therefore, we investigated the ingestion, excretion and toxicity of microplastics in the freshwater gastropod Lymnaea stagnalis. MP ingestion was analyzed as tissues levels in L. stagnalis after 6–96 h of exposure to 5–90 μm spherical polystyrene (PS) microplastics. To understand the excretion, tissue levels were determined after 24 h of exposure followed by a 12 h–7 d depuration period. To assess the toxicity, snails were exposed for 28 d to irregular PS microplastics (<63 μm, 6.4–100,000 particles mL−1), both alone and in combination with copper as additional stressor. To compare the toxicity of natural and synthetic particles, we also included diatomite particles. Microplastics ingestion and excretion significantly depended on the particle size and the exposure/depuration duration. An exposure to irregular PS had no effect on survival, reproduction, energy reserves and oxidative stress. However, we observed slight effects on immune cell phagocytosis. Exposure to microplastics did not exacerbate the reproductive toxicity of copper. In addition, there was no pronounced difference between the effects of microplastics and diatomite. The tolerance towards microplastics may originate from an adaptation of L. stagnalis to particle-rich environments or a general stress resilience. In conclusion, despite high uptake rates, PS fragments do not appear to be a relevant stressor for stress tolerant freshwater gastropods considering current environmental levels of microplastics. KW - Lymnaea stagnalis KW - Microplastic-induced effects KW - Mixture toxicity PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513551 DO - https://doi.org/10.1016/j.chemosphere.2020.128040 VL - 263 SP - 128040 PB - Elsevier Ltd. AN - OPUS4-51355 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noureen, N. A1 - Shah, F. A. A1 - Lisec, Jan A1 - Usman, H. A1 - Khalid, M. A1 - Munir, R. A1 - Zaidi, N. T1 - Revisiting the association between human leukocyte antigen and end-stage renal disease N2 - Multiple works have studied possible associations between human leukocyte antigen (HLA) alleles and end stage renal disease (ESRD) showing, however, contradictory and inconsistent results. Here, we revisit the association between ESRD and HLA antigens, comparing HLA polymorphism (at HLA-A, -B, -C, -DRB1, -DQB1 and DQA1 loci) in ESRD patients (n = 497) and controls (n = 672). Our data identified several HLA alleles that displayed a significant positive or negative association with ESRD. We also determined whether heterozygosity or homozygosity of the ESRD-associated HLA alleles at different loci could modify the prevalence of the disease. Few HLA allele combinations displayed significant associations with ESRD, among which A*3_26 combination showed the highest strength of association (OR = 4.488, P≤ 0.05) with ESRD. Interestingly, the age of ESRD onset was not affected by HLA allele combinations at different loci. We also performed an extensive literature analysis to determine whether the association of HLA to ESRD can be similar across different ethnic groups. Our analysis showed that at least certain HLA alleles, HLA-A*11, HLA-DRB1*11, and HLA-DRB1*4, display a significant association with ESRD in different ethnic groups. The findings of our study will help in determining possible protective or susceptible roles of various HLA alleles in ESRD. KW - Cancer KW - Human leukocyte antigen (HLA) KW - Renal disease PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512651 DO - https://doi.org/10.1371/journal.pone.0238878 SN - 1932-6203 VL - 15 IS - 9 SP - e0238878 AN - OPUS4-51265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lisec, Jan A1 - Jaeger, Carsten A1 - Rashid, R. A1 - Munir, R. A1 - Zaidi, N. T1 - Cancer cell lipid class homeostasis is altered under nutrient-deprivation but stable under hypoxia N2 - Background: Cancer cells modify the balance between fatty acid (FA) synthesis and uptake under metabolic stress, induced by oxygen/nutrient deprivation. These modifications were shown to alter the levels of individual triglyceride (TG) or phospholipid sub-species. To attain a holistic overview of the lipidomic profiles of cancer cells under stress we performed a broad lipidomic assay, comprising 244 lipids from six major classes. This assay allowed us to perform robust analyses and assess the changes in averages of broader lipid-classes, stratified on the basis of saturation index of their fatty-acyl side chains. Methods: Global lipidomic profiling using Liquid Chromatography-Mass Spectrometry was performed to assess lipidomic profiles of biologically diverse cancer cell lines cultivated under metabolically stressed conditions. Results: Neutral lipid compositions were markedly modified under serum-deprived conditions and, strikingly, the cellular level of triglyceride subspecies decreased with increasing number of double bonds in their fatty acyl chains. In contrast and unexpectedly, no robust changes were observed in lipidomic profiles of hypoxic (2% O2) Cancer cells despite concurrent changes in proliferation rates and metabolic gene expression. Conclusions: Serum-deprivation significantly affects lipidomic profiles of cancer cells. Although, the levels of individual lipid moieties alter under hypoxia (2% O2), the robust averages of broader lipid classes remain unchanged. KW - Tumor metabolism KW - Fatty acid metabolism KW - Lipidomic profile KW - Metabolic stress PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-481061 DO - https://doi.org/10.1186/s12885-019-5733-y SN - 1471-2407 VL - 19 SP - 501, 1 EP - 11 PB - Springer Nature AN - OPUS4-48106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kalbe, Ute A1 - Lehnik-Habrink, Petra A1 - Bandow, Nicole A1 - Sauer, Andreas T1 - Validation of European horizontal methods for the analysis of PAH, PCB and dioxins in sludge, treated biowaste and soil N2 - Draft standards for the determination of organic pollutants in the solid matter of environmental matrices such as sludge, treated biowaste and soil have been basically developed in the framework of the European standardization project HORIZONTAL. A research project financed by the German Federal Environment Agency was initiated to finalize some of these CEN standard drafts, since fully validated standard procedures are crucial for the evaluation of their reliability in the context of implementation in legislation on environmental health. Approach: Appropriate test materials (< 2mm particle size) were prepared and homogenized from contaminated soils, sludge and treated biowaste containing polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), dioxins, furans and dioxin-like-PCB and served, along with reference solutions, as the basis for international interlaboratory comparisons. Performance data of three analytical standard procedures were obtained by the statistical evaluation of results received from 11 to 29 participants per test material. Results: The overall variation coefficients of reproducibility (between-lab standard deviations) for the sum parameters were roughly between 10 and 35 %. The variation coefficients of repeatability (within-lab standard deviations) range between 3 % and 8 % and show no trend considering the substance groups or matrices. The highest coefficients of reproducibility were found for the analysis of PAHs, which were between 26 and 35 %, depending on the matrix, whereas 7-17 % reproducibility was observed for toxicity equivalents (TEQ) comprising dioxins, furans and dl-PCB. Conclusions: Overall, the results confirm that the procedures described in the Technical Specifications are fit for purpose for all three matrices and that the feasibility of the HORIZONTAL approach, to cover several matrices with one standard per analyte, was thereby proven. KW - Standardization KW - Analytical methods KW - Organic contaminants KW - Validation trial KW - Interlaboratory comparison PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-479914 DO - https://doi.org/10.1186/s12302-019-0211-3 SN - 2190-4715 VL - 31 SP - 29, 1 EP - 10 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-47991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haferkamp, Sebastian A1 - Paul, Andrea A1 - Michalchuk, Adam A1 - Emmerling, Franziska T1 - Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation N2 - The transformation of a base-catalyzed, mechano-assisted Knoevenagel condensation of mono-fluorinated benzaldehyde derivatives (p-, m-, o-benzaldehyde) with malonodinitrile was investigated in situ and in real time. Upon milling, the para-substituted product was found to crystallize initially into two different polymorphic forms, depending on the quantity of catalyst used. For low catalyst concentrations, a mechanically metastable phase (monoclinic) was initially formed, converting to the mechanically stable phase (triclinic) upon further grinding. Instead, higher catalyst concentrations crystallize directly as the triclinic product. Inclusion of catalyst in the final product, as evidenced by mass spectrometric analysis, suggests this complex polymorphic pathway may be due to seeding effects. Multivariate analysis for the in situ Raman spectra supports this complex formation pathway, and offers a new approach to monitoring multi-phase reactions during ball milling. KW - Ball milling KW - C-C coupling KW - In situ KW - Mechanochemistry KW - Multivariate data analysis PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-481872 DO - https://doi.org/10.3762/bjoc.15.110 SN - 1860-5397 VL - 15 SP - 1141 EP - 1148 PB - Beilstein Insitut CY - Frankfurt am Main AN - OPUS4-48187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Borzekowski, Antje A1 - Anggriawan, R. A1 - Auliyati, M. A1 - Kunte, Hans-Jörg A1 - Koch, Matthias A1 - Rohn, S. A1 - Karlovsky, P. A1 - Maul, Ronald T1 - Formation of Zearalenone Metabolites in Tempeh Fermentation N2 - Tempeh is a common food in Indonesia, produced by fungal fermentation of soybeans using Rhizopus sp., as well as Aspergillus oryzae, for inoculation. Analogously, for economic reasons, mixtures of maize and soybeans are used for the production of so-called tempeh-like products. For maize, a contamination with the mycoestrogen zearalenone (ZEN) has been frequently reported. ZEN is a mycotoxin which is known to be metabolized by Rhizopus and Aspergillus species. Consequently, this study focused on the ZEN transformation during tempeh fermentation. Five fungal strains of the genera Rhizopus and Aspergillus, isolated from fresh Indonesian tempeh and authentic Indonesian inocula, were utilized for tempeh manufacturing from a maize/soybean mixture (30:70) at laboratory-scale. Furthermore, comparable tempeh-like products obtained from Indonesian markets were analyzed. Results from the HPLC-MS/MS analyses show that ZEN is intensely transformed into its metabolites alpha-zearalenol (alpha-ZEL), ZEN-14-sulfate, alpha-ZEL-sulfate, ZEN-14-glucoside, and ZEN-16-glucoside in tempeh production. alpha-ZEL, being significantly more toxic than ZEN, was the main metabolite in most of the Rhizopus incubations, while in Aspergillus oryzae fermentations ZEN-14-sulfate was predominantly formed. Additionally, two of the 14 authentic samples were contaminated with ZEN, alpha-ZEL and ZEN-14-sulfate, and in two further samples, ZEN and alpha-ZEL, were determined. Consequently, tempeh fermentation of ZEN-contaminated maize/soybean mixture may lead to toxification of the food item by formation of the reductive ZEN metabolite, alpha-ZEL, under model as well as authentic conditions. KW - Modified mycotoxins KW - Zearalenone sulfate KW - a-zearalenol KW - Food fermentation KW - Rhizopus and Aspergillus oryzae PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-491126 DO - https://doi.org/10.3390/molecules24152697 VL - 24 IS - 15 SP - 2697 PB - MDPI AN - OPUS4-49112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hildebrandt, L. A1 - von der Au, Marcus A1 - Zimmermann, T. A1 - Reese, A. A1 - Ludwig, J. A1 - Pröfrock, D. T1 - A metrologically traceable protocol for the quantification of trace metals in different types of microplastic N2 - The presence of microplastic (MP) particles in aquatic environments raised concern About possible enrichment of organic and inorganic pollutants due to their specific surface and chemical properties. In particular the role of metals within this context is still poorly understood. Therefore, the aim of this work was to develop a fully validated acid digestion protocol for metal analysis in different polymers, which is a prerequisite to study such interactions. The proposed digestion protocol was validated using six different certified reference materials in the microplastic size range consisting of polyethylene, polypropylene, acrylonitrile butadiene styrene and polyvinyl chloride. As ICP-MS/MS enabled time-efficient, sensitive and robust analysis of 56 metals in one measurement, the method was suitable to provide mass fractions for a multitude of other elements beside the certified ones (As, Cd, Cr, Hg, Pb, Sb, Sn and Zn). Three different microwaves, different acid mixtures as well as different temperatures in combination with different hold times were tested for optimization purposes. With the exception of Cr in acrylonitrile butadiene styrene, recovery rates obtained using the optimized protocol for all six certified reference materials fell within a range from 95.9% ± 2.7% to 112% ± 7%. Subsequent optimization further enhanced both precision and recoveries ranging from 103% ± 5% to 107 ± 4% (U; k = 2 (n = 3)) for all certified metals (incl. Cr) in acrylonitrile butadiene styrene. The results clearly show the analytical challenges that come along with metal analysis in chemically resistant plastics. Addressing specific analysis Tools for different sorption scenarios and processes as well as the underlying kinetics was beyond this study’s scope. However, the future application of the two recommended thoroughly validated total acid digestion protocols as a first step in the direction of harmonization of metal analysis in/on MP will enhance the significance and comparability of the generated data. It will contribute to a better understanding of the role of MP as vector for trace metals in the environment. KW - Microplatic KW - Digestion KW - Analytical Chemistry PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510727 DO - https://doi.org/10.1371/journal.pone.0236120 VL - 15 IS - 7 SP - e0236120 AN - OPUS4-51072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zimmermann, T. A1 - von der Au, Marcus A1 - Reese, A. A1 - Klein, O. A1 - Hildebrandt, L. A1 - Pröfrock, D. T1 - Substituting HF by HBF4 – an optimized digestion method for multi-elemental sediment analysis via ICP-MS/MS N2 - Determination of elemental mass fractions in sediments plays a major role in evaluating the environmental status of aquatic ecosystems. Herewith, the optimization of a new total digestion protocol and the subsequent analysis of 48 elements in different sediment reference materials (NIST SRM 2702, GBW 07313, GBW 07311 and JMC-2) based on ICP-MS/MS detection is presented. The developed method applies microwave acid digestion and utilizes HBF4 as fluoride source for silicate decomposition. Similar to established protocols based on HF, HBF4 ensures the dissolution of the silicate matrix, as well as other refractory oxides. As HBF4 is not acutely toxic; no special precautions have to be made and digests can be directly measured via ICP-MS without specific sample inlet systems, evaporation steps or the addition of e.g. H3BO3, in order to mask excess HF. Different acid mixtures with and without HBF4 were evaluated in terms of digestion efficiency based on the trace metal recovery. The optimized protocol (5 mL HNO3, 2 mL HCL, 1 mL HBF4) allows a complete dissolution of the analyzed reference materials, as well as quantitative recoveries for a wide variety of certified analytes. Low recoveries for e.g. Sr, Ba and rare earth elements due to fluoride precipitation of HF-based digestions protocols, can be avoided by the usage of HBF4 instead. Based on the usage of high purity HBF4 all relevant trace, as well as matrix elements can be analyzed with sufficiently low LOQs (0.002 μg L−1 for U up to 6.7 μg L−1 for Al). In total, 34 elements were within a recovery range of 80%–120% for all three analyzed reference materials GBW 07313, GBW 07311 and JMC-2. 14 elements were outside a recovery range of 80%–120% for at least one of the analyzed reference materials. KW - Reference Materials KW - Sediment KW - HF free Digestion PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510480 DO - https://doi.org/10.1039/D0AY01049A SP - 1 EP - 10 PB - Royal Society of Chemistry AN - OPUS4-51048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kalmbach, J. A1 - Wang, Cui A1 - You, Yi A1 - Förster, C. A1 - Schubert, H. A1 - Heinze, K. A1 - Resch-Genger, Ute A1 - Seitz, M. T1 - Near-IR to near-IR upconversion luminescence in molecular chromium ytterbium salts N2 - Upconversion photoluminescence in hetero-oligonuclear metal complex architectures featuring organic ligands is an interesting but still rarely observed phenomenon, despite its great potential from a basic research and application perspective. In this context, a new photonic material consisting of molecular chromium(III) and ytterbium(III) complex Ions was developed that exhibits excitation-power density-dependent cooperative sensitization of the chromium-centered 2E/2T1 phosphorescence at approximately 775 nm after excitation of the ytterbium band 2F7/2!2F5/2 at approximately 980 nm in the solid state at ambient temperature. The upconversion process is insensitive to atmospheric oxygen and can be observed in the presence of water molecules in the crystal lattice. KW - Upconversion KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - NIR KW - Cr(III) KW - Yb(III) complex KW - Crystal KW - Triplet-triplet annihilation KW - Sensitization KW - Light harvesting PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512619 DO - https://doi.org/10.1002/anie.202007200 SN - 1433-7851 SN - 1521-3773 VL - 59 IS - 42 SP - 18804 EP - 18808 PB - Wiley CY - Weinheim AN - OPUS4-51261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, Q. A1 - Shinde, S. A1 - Grasso, G. A1 - Caroli, A. A1 - Abouhany, R. A1 - Lanzillotta, M. A1 - Pan, G. A1 - Wan, Wei A1 - Rurack, Knut A1 - Sellergren, B. T1 - Selective detection of phospholipids using molecularly imprinted fluorescent sensory core-shell particles N2 - Sphingosine-1-phosphate (S1P) is a bioactive sphingo-lipid with a broad range of activities coupled to its role in G-protein coupled receptor signalling. Monitoring of both intra and extra cellular levels of this lipid is challenging due to its low abundance and lack of robust affinity assays or sensors. We here report on fluorescent sensory core-shell molecularly imprinted polymer (MIP) particles responsive to near physiologically relevant levels of S1P and the S1P receptor modulator fingolimod phosphate (FP) in spiked human serum samples. Imprinting was achieved using the tetrabutylammonium (TBA) salt of FP or phosphatidic acid (DPPA·Na) as templates in combination with a polymerizable nitrobenzoxadiazole (NBD)-urea monomer with the dual role of capturing the phospho-anion and signalling its presence. The monomers were grafted from ca 300 nm RAFT-modified silica core particles using ethyleneglycol dimethacrylate (EGDMA) as crosslinker resulting in 10–20 nm thick shells displaying selective fluorescence response to the targeted lipids S1P and DPPA in aqueous buffered media. Potential use of the sensory particles for monitoring S1P in serum was demonstrated on spiked serum samples, proving a linear range of 18–60 μM and a detection limit of 5.6 μM, a value in the same range as the plasma concentration of the biomarker. KW - Molecularly imprinted polymers KW - Phospholipids KW - Fluorescence KW - Dye monomers PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509485 DO - https://doi.org/10.1038/s41598-020-66802-3 SN - 2045-2322 VL - 10 IS - 1 SP - 9924 PB - Nature Research CY - London AN - OPUS4-50948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moll, J. A1 - Wang, Cui A1 - Päpcke, A. A1 - Förster, C. A1 - Resch-Genger, Ute A1 - Lochbrunner, S. A1 - Heinze, K. T1 - Green Light Activation of Push-Pull Ruthenium(II) Complexes N2 - Synthesis, characterization, electrochemistry, and photophysics of novel homo- and heteroleptic ruthenium(II) complexes [Ru(cpmp)2] 2+ (22+) and [Ru(cpmp)(ddpd)]2+ (32+) bearing the tridentate ligands 6,2’’-carboxypyridyl-2,2’-methylamine-pyridylpyridine (cpmp) and N,N’-dimethyl-N,N’-dipyridin-2-ylpyridine-2,6-diamine (ddpd) are reported. The complexes possess one (32+) or two (22+) electron-deficient dipyridyl ketone fragments as electron accepting sites enabling intraligand charge transfer (ILCT), ligand-toligand charge transfer (LL’CT) and low-energy metal-to-ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). 22+ shows 3MLCT phosphorescence in the red to near-infrared spectral region at room temperature in deaerated acetonitrile solution with an emission quantum yield of 1.3 % and a 3MLCT lifetime of 477 ns, while 3 2+ is much less luminescent. This different behaviour is ascribed to the energy gap law and the shape of the parasitic excited 3MC state potential energy surface. This study highlights the importance of the excited state energies and geometries for the actual excited state dynamics. Aromatic and aliphatic amines reductively quench the excited state of 22+ paving the way to photocatalytic applications using low-energy green light as exemplified with the green-light sensitized thiol-ene click reaction. KW - Green light excitation KW - Ruthenium(II) complexes KW - Phosphorescence KW - MLCT KW - Photoinduced electron transfer PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506759 DO - https://doi.org/10.1002/chem.202000871 SP - 1 EP - 13 PB - Wiley-VCH Verlag AN - OPUS4-50675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Faßbender, Sebastian A1 - Rodiouchkina, K. A1 - Vanhaecke, F. A1 - Meermann, Björn T1 - Method development for on-line species-specific sulfur isotopic analysis by means of capillary electrophoresis/multicollector ICP-mass spectrometry N2 - In this work, a method for species-specific isotopic analysis of sulfur via capillary electrophoresis hyphenated on-line with multicollector ICP-MS (CE/MC-ICP-MS) was developed. Correction for the mass bias caused by instrumental mass discrimination was realized via external correction with multiple-injection sample-standard bracketing. By comparing the isotope ratio measurement results obtained using the newly developed on-line CE/MC-ICP-MS method with those obtained via traditional MC-ICP-MS measurement after analyte/matrix separation by anion exchange chromatography for isotopic reference materials and an in-house bracketing standard, the most suitable data evaluation method could be identified. The repeatability for the sulfate-δ34S value (calculated from 18 measurements of a standard conducted over seven measurement sessions) was 0.57‰ (2SD) and thereby only twice that obtained with off-line measurements (0.30‰, n = 68). As a proof of concept for analysis of samples with a real matrix, the determination of the sulfur isotopic composition of naturally present sulfate was performed for different river systems. The CE/MC-ICP-MS results thus obtained agreed with the corresponding off-line MC-ICP-MS results within the 2SD ranges, and the repeatability of consecutive δ34S measurements (n = 3) was between 0.3‰ and 1.3‰ (2SD). Finally, the isotopic analysis of two different S-species in a river water sample spiked with 2-pyridinesulfonic acid (PSA) was also accomplished. KW - River water sulfate KW - Environmental speciation KW - Sulfur isotopes KW - On-line CE/MC-ICP-MS KW - Multiple-injection sample-standard bracketing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509549 DO - https://doi.org/10.1007/s00216-020-02781-8 SN - 1618-2642 VL - 412 IS - 23 SP - 5637 EP - 5646 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-50954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krahl, T. A1 - Beer, F. A1 - Relling, A. A1 - Gawlitza, Kornelia A1 - Rurack, Knut A1 - Kemnitz, E. T1 - Toward Luminescent Composites by Phase Transfer of SrF2 :Eu3+ Nanoparticles Capped with Hydrophobic Antenna Ligands N2 - Transparent dispersions of hydrophobic SrF2 :Eu3+ nanoparticles in cyclohexane with up to 20% europium were obtained by fluorolytic sol-gel synthesis followed by Phase transfer into cyclohexane through capping with sodium dodecylbenzenesulfonate (SDBS). The particles were characterized by TEM, XRD and DLS as spherical objects with a diameter between 6 and 11 nm in dry state. 1H-13CP MAS NMR experiments revealed the binding of the anionic sulfonate head group to the particle surface. The particles show bright red luminescence upon excitation of the aromatic capping agents, acting as antennas for an Energy transfer from the benzenesulfonate unit to the Eu3+ centers in the particles. This synthesis method overcomes the current obstacle of the fluorolytic sol-gel synthesis that transparent dispersions can be obtained directly only in hydrophilic solvents. To demonstrate the potential of such hydrophobized alkaline-earth fluoride particles, transparent luminescent organic-inorganic composites with 10% SrF2 :Eu3+ embedded into polyTEGDMA, polyBMA, poly-BDDMA and polyD3MA, respectively, were prepared, endowing the polymers with the luminescence features of the nanoparticles. KW - Nanoparticles KW - Fluorides KW - Sol-gel process KW - Organic-inorganic hybrid composites PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508668 DO - https://doi.org/10.1002/cnma.202000058 SP - 1 EP - 11 PB - Wiley AN - OPUS4-50866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Biesen, L. A1 - Nirmalananthan-Budau, Nithiya A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Müller, T. J. J. T1 - Solid-State Emissive Aroyl-S,N-Ketene Acetals with Tunable N2 - N-Benzyl aroyl-S,N-ketene acetals can be readily synthesized by condensation of aroyl chlorides and N-Benzyl 2-methyl benzothiazolium salts in good to excellent yields, yielding a library of 35 chromophores with bright solid-state emission and aggregation-induced emission characteristics. Varying the substituent from electron-donating to electronwithdrawing enables the tuning of the solid-state emission Color from deep blue to red. KW - Nano KW - Nanoparticle KW - Photoluminescence KW - Fluorescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - dye KW - Enhancement KW - Particle KW - Polarity KW - AIE KW - Aggregation KW - Aggregation-induced emission KW - Solid state emission PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509072 DO - https://doi.org/10.1002/anie.201916396 VL - 59 IS - 25 SP - 10037 EP - 10041 PB - Wiley Online Libary AN - OPUS4-50907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Nirmalananthan-Budau, Nithiya A1 - Resch-Genger, Ute T1 - Fluorescence calibration standards made from broadband emitters encapsulated in polymer beads for fluorescence microscopy and flow cytometry N2 - We present here the design and characterization of a set of spectral calibration beads. These calibration beads are intended for the determination and regular control of the spectral characteristics of fluorescence microscopes and other fluorescence measuring devices for the readout of bead-based assays. This set consists of micrometer-sized polymer beads loaded with dyes from the liquid Calibration Kit Spectral Fluorescence Standards developed and certified by BAM for the wavelength-dependent Determination of the spectral responsivity of fluorescencemeasuring devices like spectrofluorometers. To cover the wavelength Region from 400 to 800 nm, two new near-infrared emissive dyes were included, which were spectroscopically characterized in solution and encapsulated in the beads. The resulting set of beads presents the first step towards a new platform of spectral calibration beads for the determination of the spectral characteristics of fluorescence instruments like fluorescence microscopes, FCM setups, and microtiter plate readers, thereby meeting the increasing demand for reliable and comparable fluorescence data especially in strongly regulated areas, e.g., medical diagnostics. This will eventually provide the basis for standardized calibration procedures for imaging systems as an alternative to microchannel slides containing dye solutions previously reported by us. KW - Fluorescence standard KW - Fluorescence KW - Dye KW - Microscopy KW - Bead KW - Particle KW - NIR KW - calibration KW - Quality assurance KW - Traceability PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508117 DO - https://doi.org/10.1007/s00216-020-02664-y SN - 1618-2642 VL - 412 IS - 24 SP - 6499 EP - 6507 PB - Springer AN - OPUS4-50811 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kirilina, E. A1 - Helbling, S. A1 - Morawski, M. A1 - Pine, K. A1 - Reimann, K. A1 - Jankuhn, S. A1 - Dinse, J. A1 - Deistung, A. A1 - Reichenbach, J. R. A1 - Trampel, R. A1 - Geyer, S. A1 - Müller, Larissa A1 - Jakubowski, Norbert A1 - Arendt, T. A1 - Bazin, P.-L. A1 - Weiskopf, N. T1 - Superficial white matter imaging: Contrast mechanisms and whole-brain in vivo mapping N2 - Superficial white matter (SWM) contains the most cortico-cortical white matter connections in the human brain encompassing the short U-shaped association fibers. Despite its importance for brain connectivity, very little is known about SWM in humans, mainly due to the lack of noninvasive imaging methods. Here, we lay the groundwork for systematic in vivo SWM mapping using ultrahigh resolution 7 T magnetic resonance imaging. Using biophysical modeling informed by quantitative ion beam microscopy on postmortem brain tissue, we demonstrate that MR contrast in SWM is driven by iron and can be linked to the microscopic iron distribution. Higher SWM iron concentrations were observed in U-fiber–rich frontal, temporal, and parietal areas, potentially reflecting high fiber density or late myelination in these areas. Our SWM mapping approach provides the foundation for systematic studies of interindividual differences, plasticity, and pathologies of this crucial structure for cortico-cortical connectivity in humans. KW - Magnetic resonance imaging KW - Laser ablation KW - ICP-MS KW - Brain KW - Imaging PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514430 DO - https://doi.org/10.1126/sciadv.aaz9281 SN - 2375-2548 VL - 6 IS - 41 SP - eaaz9281 PB - American Association for the Advancement of Science (Science/AAAS) CY - Washington, DC, USA AN - OPUS4-51443 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neamtu, M. A1 - Nadejde, C. A1 - Brinza, L. A1 - Dragos, O. A1 - Gherghel, D. A1 - Paul, Andrea T1 - Iron phthalocyanine-sensitized magnetic catalysts for BPA photodegradation N2 - The catalytic behavior of iron phthalocyanine (FePc)-sensitized magnetic nanocatalysts was evaluated for their application in the oxidative treatment of Bisphenol A (BPA) under mild environmental conditions. Two types of FePc (Fe(II)Pc and Fe(III)Pc), which are highly photosensitive compounds, were immobilized on the surface of functionalized magnetite. The nanomaterials were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray difraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA). The generation of singlet Oxygen by nanomaterials was also investigated. In the presence of UVA light exposure (365nm) and 15mM H2O2, the M@Fe(III)Pc photocatalyst gave the best results; for a catalyst concentration of 2.0gL −1, around 60% BPA was removed after 120min of reaction. These experimental conditions were further tested under natural solar light exposure, for which also M@Fe(III)Pc exhibited enhanced oxidative catalytic activity, being able to remove 83% of BPA in solution. The water samples were less cytotoxic after treatment, this being confrmed by the MCF-7 cell viability assay. KW - Photosensitization KW - magnetic nanocatalysts KW - BPA removal PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506368 DO - https://doi.org/10.1038/s41598-020-61980-6 VL - 10 IS - 1 SP - 5376 AN - OPUS4-50636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmid, Thomas A1 - Jungnickel, Robert A1 - Dariz, P. T1 - Insights into the CaSO4–H2O System: A Raman-Spectroscopic Study N2 - Even though being the subject of natural scientific research for many decades, the system CaSO4–H2O, consisting of the five crystalline phases gypsum, bassanite, and the anhydrites III, II, and I, has left many open questions for research. Raman spectroscopy was used because of its structural sensitivity and in situ measurement capability to obtain further insight by studying phase transitions in both ex situ and in situ experiments. The findings include significant contributions to the completeness and understanding of Raman spectroscopic data of the system. The dehydration path gypsum–bassanite–anhydrite III was shown to have strong parallels to a physical drying process, which depends on many parameters beyond the burning temperature. Raman band width determination was demonstrated to enable the quantitative discrimination of α-bassanite and β-bassanite as well as the postulated three sub-forms of anhydrite II (AII), which are all based on differences in crystallinity. In the latter case, the observed continuous structural variations over increasing burning temperatures were elucidated as a combination of decreasing surface areas and healing of crystal lattice defects. We propose an only two-fold sub-division of AII into reactive “disordered AII” and much less reactive “crystalline AII” with a transition temperature of 650°C ± 50 K. KW - Gypsum KW - Bassanite KW - Hemihydrate KW - Anhydrite KW - Raman spectroscopy PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506701 DO - https://doi.org/10.3390/min10020115 SN - 2075-163X VL - 10 IS - 2 SP - 115, 35 PB - MDPI CY - Basel AN - OPUS4-50670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartelmeß, Jürgen A1 - Valderrey, Virginia A1 - Rurack, Knut T1 - Development of a “Turn-on” Fluorescent Probe-Based Sensing System for Hydrogen Sulfide in Liquid and Gas Phase N2 - A “turn-on” fluorescence sensing system based on a BODIPY-cobaloxime complex for the detection of H2S in liquid and gas phase was developed. To that aim, two cobaloxime complexes bearing an axial pyridyl-BODIPY ligand were initially evaluated as sensitive fluorescent HS− indicators in aqueous solution. The sensing mechanism involves the selective substitution of the BODIPY ligand by the HS− anion at the cobalt center, which is accompanied by a strong fluorescence enhancement. The selection of a complex with an ideal stability and reactivity profile toward HS− relied on the optimal interaction between the cobalt metal-center and two different pyridyl BODIPY ligands. Loading the best performing BODIPY-cobaloxime complex onto a polymeric hydrogel membrane allowed us to study the selectivity of the probe for HS− against different anions and cysteine. Successful detection of H2S by the fluorescent “light-up” membrane was not only accomplished for surface water but could also be demonstrated for relevant H2S concentrations in gas phase. KW - Sulfide sensing KW - Fluorescence KW - BODIPYs KW - Cobaloxime complex KW - Gas sensing PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-492186 DO - https://doi.org/10.3389/fchem.2019.00641 SN - 2296-2646 VL - 7 SP - Art. Nr. 641 PB - Frontiers Media CY - Lausanne AN - OPUS4-49218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reimann, C. A1 - Kaufmann, Jan Ole A1 - Adams, L. C. A1 - Onthank, D. C. A1 - Thöne-Reineke, C. A1 - Robinson, S. P. A1 - Hamm, B. A1 - Botnar, R. M. A1 - Makowski, M. R. T1 - Dual-probe molecular MRI for the in vivo characterization of atherosclerosis in a mouse model: Simultaneous assessment of plaque inflammation and extracellular-matrix remodeling N2 - Molecular MRI is a promising in-vivo modality to detect and quantify morphological and molecular vessel-wall changes in atherosclerosis. The combination of different molecular biomarkers may improve the risk stratification of patients. This study aimed to investigate the feasibility of simultaneous visualization and quantification of plaque-burden and inflammatory activity by dual-probe molecular MRI in a mouse-model of progressive atherosclerosis and in response-to-therapy. Homozygous apolipoprotein E knockout mice (ApoE−/−) were fed a high-fat-diet (HFD) for up to four-months prior to MRI of the brachiocephalic-artery. To assess response-to-therapy, a statin was administered for the same duration. MR imaging was performed before and after administration of an elastin-specific gadolinium-based and a macrophage-specific iron-oxide-based probe. Following in-vivo MRI, samples were analyzed using histology, immunohistochemistry, inductively-coupled-mass-spectrometry and laser-inductively-coupled-mass-spectrometry. In atherosclerotic-plaques, intraplaque expression of elastic-fibers and inflammatory activity were not directly linked. While the elastin-specific probe demonstrated the highest accumulation in advanced atherosclerotic-plaques after four-months of HFD, the iron-oxide-based probe showed highest accumulation in early atherosclerotic-plaques after two-months of HFD. In-vivo measurements for the elastin and iron-oxide-probe were in good agreement with ex-vivo histopathology (Elastica-van-Giesson stain: y = 298.2 + 5.8, R2 = 0.83, p < 0.05; Perls‘ Prussian-blue-stain: y = 834.1 + 0.67, R2 = 0.88, p < 0.05). Contrast-to-noise-ratio (CNR) measurements of the elastin probe were in good agreement with ICP-MS (y = 0.11x-11.3, R² = 0.73, p < 0.05). Late stage atherosclerotic-plaques displayed the strongest increase in both CNR and gadolinium concentration (p < 0.05). The gadolinium probe did not affect the visualization of the iron-oxide-probe and vice versa. This study demonstrates the feasibility of simultaneous assessment of plaque-burden and inflammatory activity by dual-probe molecular MRI of progressive atherosclerosis. The in-vivo detection and quantification of different MR biomarkers in a single scan could be useful to improve characterization of atherosclerotic-lesions. KW - In-vivo KW - Molecular MRI PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-492514 DO - https://doi.org/10.1038/s41598-019-50100-8 VL - 9 IS - 1 SP - Article number: 13827 PB - Nature AN - OPUS4-49251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sebald, M.A. A1 - Gebauer, J. A1 - Sommerfeld, Thomas A1 - Koch, Matthias T1 - First Synthesis of (−)-Altenuene-D3 Suitable as Internal Standard for Isotope Dilution Mass Spectrometry N2 - Metabolites from Alternaria fungi exhibit a variety of biological properties such as phytotoxic, cytotoxic, or antimicrobial activity. Optimization of a literature procedure culminated in an efficient total synthesis of (−)-altenuene as well as a stable isotope-labeled derivative suitable for implementation in a LC-MS/MS method for mycotoxin analysis. KW - Altenuene KW - Alternaria mycotoxins KW - Food safety KW - Isotope-labeled KW - SIDA-LC-MS/MS KW - Suzuki coupling PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-500696 DO - https://doi.org/10.3390/molecules24244563 SN - 1420-3049 VL - 24 SP - 4563 PB - MDPI CY - Basel AN - OPUS4-50069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gharaati, S. A1 - Wang, Cui A1 - Förster, C. A1 - Weigert, Florian A1 - Resch-Genger, Ute A1 - Heinze, K. T1 - Triplet–Triplet Annihilation Upconversion in a MOF with AcceptorFilled Channels N2 - In summary, we report a highly modular solid TTA-UC system comprising of a crystalline, thermally stable PCN222(Pd) MOF with CA-coated MOF channels and with a DPA annihilator embedded in a solution-like environment in the MOF channels. This solid material displays blue upconverted delayed emission with a luminescence lifetime of 373 us, a threshold value of 329 mW*cm-2 and a triplet–triplet energy transfer efficiency of 82%. This optical application adds another facet to the versatile chemistry of PCN-222 MOFs. The design concept is also applicable to other TTA-UC pairs and enables tuning of the UCL color, for example, by replacing DPA with other dyes as exemplarily shown for 2,5,8,11-tetra-tert-butyl-perylene, that yields UCL at 450 nm. Current work aims to reduce the oxygen sensitivity and to increase the retention of the trapped annihilators in organic environments, for example, by tuning the chain length of the carboxylic acid and by coating the MOF surface. In addition, the TTA-UC efficiency will be further enhanced by reducing the reabsorption of the UC emission caused by Pd(TCPP) and by optimizing the sensitizer/annihilator interface. KW - Porphyrin KW - Method KW - MOF KW - Fluorescence KW - Dye KW - Sensor KW - Oxygen sensitive KW - Single molecule KW - DPA KW - Lifetime KW - Upconverstion KW - Quantum yield KW - Triplet-triplet annihilation KW - Sensitization KW - Energy transfer KW - NMR PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-500580 DO - https://doi.org/10.1002/chem.201904945 VL - 26 IS - 5 SP - 1003 EP - 1007 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-50058 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zettner, Alina A1 - Gojani, Ardian A1 - Schmid, Thomas A1 - Gornushkin, Igor B. T1 - Evaluation of a Spatial Heterodyne Spectrometer for Raman Spectroscopy of Minerals N2 - Spatial heterodyne spectroscopy (SHS) is a novel spectral analysis technique that is being applied for Raman spectroscopy of minerals. This paper presents the theoretical basis of SHS and its application for Raman measurements of calcite, quartz and forsterite in marble, copper ore and nickel ore, respectively. The SHS measurements are done using a broadband (518–686 nm) and resolving power R ≈ 3000 instrument. The spectra obtained using SHS are compared to those obtained by benchtop and modular dispersive spectrometers. It is found that SHRS performance in terms of resolution is comparable to that of the benchtop spectrometer and better than the modular dispersive spectrometer, while the sensitivity of SHRS is worse than that of a benchtop spectrometer, but better than that of a modular dispersive spectrometer. When considered that SHS components are small and can be packaged into a handheld device, there is interest in developing an SHS-based Instrument for mobile Raman spectroscopy. This paper evaluates the possibility of such an application. KW - Forsterite KW - Spatial heterodyne spectrometer KW - Interferometric spectroscopy KW - Fourier transform spectroscopy KW - Raman spectroscopy KW - Calcite KW - Quartz PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504624 DO - https://doi.org/10.3390/min10020202 VL - 10 IS - 2 SP - 202 PB - MDPI CY - Basel, Switzerland AN - OPUS4-50462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ebel, Kenny A1 - Bald, Ilko T1 - Length and Energy Dependence of Low-Energy Electron-Induced Strand Breaks in Poly(A) DNA N2 - The DNA in living cells can be effectively damaged by high-energy radiation, which can lead to cell death. Through the ionization of water molecules, highly reactive secondary species such as low-energy electrons (LEEs) with the most probable energy around 10 eV are generated, which are able to induce DNA strand breaks via dissociative electron attachment. Absolute DNA strand break cross sections of specific DNA sequences can be efficiently determined using DNA origami nanostructures as platforms exposing the target sequences towards LEEs. In this paper, we systematically study the effect of the oligonucleotide length on the strand break cross section at various irradiation energies. The present work focuses on poly-adenine sequences (d(A4), d(A8), d(A12), d(A16), and d(A20)) irradiated with 5.0, 7.0, 8.4, and 10 eV electrons. Independent of the DNA length, the strand break cross section shows a maximum around 7.0 eV electron energy for all investigated oligonucleotides confirming that strand breakage occurs through the initial formation of negative ion resonances. When going from d(A4) to d(A16), the strand break cross section increases with oligonucleotide length, but only at 7.0 and 8.4 eV, i.e., close to the maximum of the negative ion resonance, the increase in the strand break cross section with the length is similar to the increase of an estimated geometrical cross section. For d(A20), a markedly lower DNA strand break cross section is observed for all electron energies, which is tentatively ascribed to a conformational change of the dA20 sequence. The results indicate that, although there is a general length dependence of strand break cross sections, individual nucleotides do not contribute independently of the absolute strand break cross section of the whole DNA strand. The absolute quantification of sequence specific strand breaks will help develop a more accurate molecular level understanding of radiation induced DNA damage, which can then be used for optimized risk estimates in cancer radiation therapy. KW - DNA origami KW - DNA radiation damage KW - DNA strand breaks KW - Low-energy electrons KW - Sequence dependence PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503563 DO - https://doi.org/10.3390/ijms21010111 VL - 21 IS - 1 SP - 1 EP - 11 PB - MDPI CY - Basel, Switzerland AN - OPUS4-50356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kneipp, Janina A1 - Zancajo, Victor M.R. A1 - Diehn, S. A1 - Filiba, N. A1 - Elbaum, R. T1 - Spectroscopic Discrimination of Sorghum Silica Phytoliths N2 - Grasses accumulate silicon in the form of silicic acid, which is precipitated as amorphous silica in microscopic particles termed phytoliths. These particles comprise a variety of morphologies according to the cell type in which the silica was deposited. Despite the evident morphological differences, phytolith chemistry has mostly been analysed in bulk samples, neglecting differences between the varied types formed in the same species. In this work, we extracted leaf phytoliths from mature plants of Sorghum bicolor (L.) Moench. Using solid state NMR and thermogravimetric analysis, we show that the extraction methods alter greatly the silica molecular structure, its condensation degree and the trapped organic matter. Measurements of individual phytoliths by Raman and synchrotron FTIR microspectroscopies in combination with multivariate analysis separated bilobate silica cells from prickles and long cells, based on the silica molecular structures and the fraction and composition of occluded organic matter. The variations in structure and composition of sorghum phytoliths suggest that the biological pathways leading to silica deposition vary between these cell types. KW - Phytoliths KW - Biosilicification KW - Raman KW - Sorghum KW - Solid state NMR KW - Synchrotron FTIR PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502672 DO - https://doi.org/10.3389/fpls.2019.01571 VL - 10 SP - 1571 PB - Frontiers Media CY - Lausanne AN - OPUS4-50267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tjaden, B. A1 - Lisec, Jan A1 - Schramm, A. T1 - N-Myc-induced metabolic rewiring creates novel therapeutic vulnerabilities in neuroblastoma N2 - N-Myc is a transcription factor that is aberrantly expressed in many tumor types and is often correlated with poor patient prognosis. Recently, several lines of evidence pointed to the fact that oncogenic activation of Myc family proteins is concomitant with reprogramming of tumor cells to cope with an enhanced need for metabolites during cell growth. These adaptions are driven by the ability of Myc proteins to act as transcriptional amplifiers in a tissue-of-origin specific manner. Here, we describe the effects of N-Myc overexpression on metabolic reprogramming in neuroblastoma cells. Ectopic expression of N-Myc induced a glycolytic switch that was concomitant with enhanced sensitivity towards 2-deoxyglucose, an inhibitor of glycolysis. Moreover, global metabolic profiling revealed extensive alterations in the cellular metabolome resulting from overexpression of N-Myc. Limited supply with either of the two main carbon sources, glucose or glutamine, resulted in distinct shifts in steady-state metabolite levels and significant changes in glutathione metabolism. Interestingly, interference with glutamine-glutamate conversion preferentially blocked proliferation of N-Myc overexpressing cells, when glutamine levels were reduced. Thus, our study uncovered N-Myc induction and nutrient levels as important metabolic master switches in neuroblastoma cells and identified critical nodes that restrict tumor cell proliferation. KW - Mass-Spectrometry KW - Cancer KW - MYCN PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507193 DO - https://doi.org/10.1038/s41598-020-64040-1 VL - 10 IS - 1 SP - 7157 AN - OPUS4-50719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, J. A1 - Tarábek, J. A1 - Kulkarni, R. A1 - Wang, Cui A1 - Dračínský, M. A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard A1 - Resch-Genger, Ute A1 - Bojdys, M. J. T1 - A π-conjugated, covalent phosphinine framework N2 - Structural modularity of polymer frameworks is a key advantage of covalent organic polymers, however, only C, N, O, Si and S have found their way into their building blocks so far. Here, we expand the toolbox available to polymer and materials chemists by one additional nonmetal, phosphorus. Starting with a building block that contains a λ⁵‐phosphinine (C₅P) moiety, we evaluate a number of polymerisation protocols, finally obtaining a π‐conjugated, covalent phosphinine‐based framework (CPF‐1) via Suzuki‐Miyaura coupling. CPF‐1 is a weakly porous polymer glass (72.4 m2 g‐1 N2 BET at 77 K) with green fluorescence (λmax 546 nm) and extremely high thermal stability. The polymer catalyzes hydrogen evolution from water under UV and visible light irradiation without the need for additional co‐catalyst at a rate of 33.3 μmol h‐¹ g‐¹. Our results demonstrate for the first time the incorporation of the phosphinine motif into a complex polymer framework. Phosphinine‐based frameworks show promising electronic and optical properties that might spark future interest in their applications in light‐emitting devices and heterogeneous catalysis. KW - Phosphinine KW - Fully aromatic frameworks KW - Suzuki-Miyaura coupling KW - Polymers KW - Fluorescence KW - Small-angle scattering PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-485330 DO - https://doi.org/10.1002/chem.201900281 SP - 2 EP - 10 PB - Wiley VCH-Verlag CY - Weinheim AN - OPUS4-48533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schürmann, Robin A1 - Ebel, Kenny A1 - Nicolas, C. A1 - Milosavljevic, A. R. A1 - Bald, Ilko T1 - Role of valence band states and plasmonic enhancement in electron-transfer-induced transformation of nitrothiophenol N2 - Hot-electron-induced reactions are more and more recognized as a critical and ubiquitous reaction in heterogeneous catalysis. However, the kinetics of these reactions is still poorly understood, which is also due to the complexity of plasmonic nanostructures. We determined the reaction rates of the hot-electron-mediated reaction of 4-nitrothiophenol (NTP) on gold nanoparticles (AuNPs) using fractal kinetics as a function of the laser wavelength and compared them with the plasmonic enhancement of the system. The reaction rates can be only partially explained by the plasmonic response of the NPs. Hence, synchrotron X-ray photoelectron spectroscopy (XPS) measurements of isolated NTP-capped AuNP clusters have been performed for the first time. In this way, it was possible to determine the work function and the accessible valence band states of the NP systems. The results show that besides the plasmonic enhancement, the reaction rates are strongly influenced by the local density of the available electronic states of the system. KW - Photocatalytic reduction KW - Raman-spectroscopy KW - Hot-electrons KW - Work function KW - Surface KW - Nanaoparticles KW - Scattering KW - Molecule KW - Carriers KW - Layers PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-486464 DO - https://doi.org/10.1021/acs.jpclett.9b00848 SN - 1948-7185 VL - 10 IS - 11 SP - 3153 EP - 3158 PB - American Chemical Society CY - Washington, DC AN - OPUS4-48646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heck, Christian A1 - Kanehira, Y. A1 - Kneipp, Janina A1 - Bald, Ilko T1 - Amorphous Carbon Generation as a Photocatalytic Reaction on DNA-Assembled Gold and Silver Nanostructures N2 - Background signals from in situ-formed amorphous carbon, despite not being fully understood, are known to be a common issue in few-molecule surface-enhanced Raman scattering (SERS). Here, discrete gold and silver nanoparticle aggregates assembled by DNA origami were used to study the conditions for the formation of amorphous carbon during SERS measurements. Gold and silver dimers were exposed to laser light of varied power densities and wavelengths. Amorphous carbon prevalently formed on silver aggregates and at high power densities. Time-resolved measurements enabled us to follow the formation of amorphous carbon. Silver nanolenses consisting of three differently-sized silver nanoparticles were used to follow the generation of amorphous carbon at the single-nanostructure level. This allowed observation of the many sharp peaks that constitute the broad amorphous carbon signal found in ensemble measurements. In conclusion, we highlight strategies to prevent amorphous carbon formation, especially for DNA-assembled SERS substrates. KW - Amorphous carbon KW - DNA origami KW - SERS KW - Nanoparticle dimers KW - Nanolenses PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-486484 DO - https://doi.org/10.3390/molecules24122324 SN - 1420-3049 VL - 24 IS - 12 SP - Article Number: 2324-1 EP - 10 PB - MDPI AN - OPUS4-48648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geißler, Daniel A1 - Wegmann, Marc A1 - Jochum, T. A1 - Somma, V. A1 - Sowa, M. A1 - Scholz, J. A1 - Fröhlich, E. A1 - Hoffmann, Katrin A1 - Niehaus, J. A1 - Roggenbuck, D. A1 - Resch-Genger, Ute T1 - An automatable platform for genotoxicity testing of nanomaterials based on the fluorometric γ-H2AX assay reveals no genotoxicity of properly surface-shielded cadmium-based quantum dots N2 - The large number of nanomaterial-based applications emerging in the materials and life sciences and the foreseeable increasing use of these materials require methods that evaluate and characterize the toxic potential of these nanomaterials to keep safety risks to people and environment as low as possible. As nanomaterial toxicity is influenced by a variety of parameters like size, shape, chemical composition, and surface chemistry, high throughput screening (HTS) platforms are recommended for assessing cytotoxicity. Such platforms are not yet available for genotoxicity testing. Here, we present first results obtained for application-relevant nanomaterials using an automatable genotoxicity platform that relies on the quantification of the phosphorylated histone H2AX (γ-H2AX) for detecting DNA double strand breaks (DSBs) and the automated microscope system AKLIDES® for measuring integral fluorescence intensities at different excitation wavelengths. This platform is used to test the genotoxic potential of 30 nm-sized citrate-stabilized gold nanoparticles (Au-NPs) as well as micellar encapsulated iron oxide nanoparticles (FeOx-NPs) and different cadmium (Cd)-based semiconductor quantum dots (QDs), thereby also searching for positive and negative controls as reference materials. In addition, the influence of the QD shell composition on the genotoxic potential of these Cd-based QDs was studied, using CdSe cores as well as CdSe/CdS core/shell and CdSe/CdS/ZnS core/shell/shell QDs. Our results clearly revealed the genotoxicity of the Au-NPs and its absence in the FeOx-NPs. The genotoxicity of the Cd-QDs correlates with the shielding of their Cd-containing core, with the core/shell/shell architecture preventing genotoxicity risks. The fact that none of these nanomaterials showed cytotoxicity at the chosen particle concentrations in a conventional cell viability assay underlines the importance of genotoxicity studies to assess the hazardous potential of nanomaterials. KW - Nanomaterial KW - Genotoxicity testing KW - γ-H2AX assay KW - Quantum dot PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-486318 DO - https://doi.org/10.1039/C9NR01021A SN - 2040-3372 SN - 2040-3364 VL - 11 IS - 28 SP - 13458 EP - 13468 PB - The Royal Society of Chemistry AN - OPUS4-48631 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kotthoff, Lisa A1 - Lisec, Jan A1 - Schwerdtle, T. A1 - Koch, Matthias T1 - Prediction of transformation products of monensin by electrochemistry compared to microsomal assay and hydrolysis N2 - The knowledge of transformation pathways and identification of transformation products (TPs) of veterinary drugs is important for animal health, food, and environmental matters. The active agent Monensin (MON) belongs to the ionophore antibiotics and is widely used as a veterinary drug against coccidiosis in broiler farming. However, no electrochemically (EC) generated TPs of MON have been described so far. In this study, the online coupling of EC and mass spectrometry (MS) was used for the generation of oxidative TPs. EC-conditions were optimized with respect to working electrode material, solvent, modifier, and potential polarity. Subsequent LC/HRMS (liquid chromatography/high resolution mass spectrometry) and MS/MS experiments were performed to identify the structures of derived TPs by a suspected target analysis. The obtained EC-results were compared to TPs observed in metabolism tests with microsomes and hydrolysis experiments of MON. Five previously undescribed TPs of MON were identified in our EC/MS based study and one TP, which was already known from literature and found by a microsomal assay, could be confirmed. Two and three further TPs were found as products in microsomal tests and following hydrolysis, respectively. We found decarboxylation, O-demethylation and acid-catalyzed ring-opening reactions to be the major mechanisms of MON transformation. KW - Transformation products KW - Monensin KW - Veterinary drugs KW - Electrochemistry KW - Hydrolysis KW - LC/HRMS PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-485689 DO - https://doi.org/10.3390/molecules24152732 SN - 1420-3049 VL - 24 IS - 15 SP - 2732, 1 EP - 12 PB - MDPI CY - Basel AN - OPUS4-48568 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Brunet, G. A1 - Marin, R. A1 - Monk, Melissa-Jane A1 - Galico, D. A. A1 - Sigoli, F. A. A1 - Suturina, E. A. A1 - Hemmer, E. A1 - Murugesu, M. T1 - Exploring the dual functionality of an Ytterbium complex for luminescence thermometry and slow magnetic relaxation† N2 - We present a comprehensive investigation of the magnetic and optical properties of an ytterbium complex, which combines two desirable and practical features into a single molecular system. Based upon YbIII Ions that promote near-infrared optical activity and a chemical backbone that is ideal for an in-depth understanding of the magnetic behaviour, we have designed a multifunctional opto-magnetic species that operates as a luminescent thermometer and as a single-molecule magnet (SMM). Our magnetic investigations, in conjunction with ab initio calculations, reveal one of the highest energy barriers reported for an YbIII-based complex. Moreover, we correlate this anisotropic barrier with the Emission spectrum of the compound, wherein we provide a complete assignment of the energetic profile of the complex. Such studies lay the foundation for the design of exciting multi-faceted materials that are able to retain information at the single-molecule level and possess built-in thermal self-monitoring capabilities. KW - Magnetic KW - Fluorescence KW - NIR KW - Temperature KW - Dual sensing KW - Sensor KW - Yb(III) complex KW - Lanthanide KW - Quantum yield KW - Quality assurance PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-486659 DO - https://doi.org/10.1039/c9sc00343f VL - 10 IS - 28 SP - 6799 EP - 6808 PB - Royal Society of Chemistry AN - OPUS4-48665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmid, Thomas A1 - Dariz, P. T1 - Raman Microspectroscopic Imaging of Binder Remnants in Historical Mortars Reveals Processing Conditions N2 - Binder remnants in historical mortars represent a record of the connection between the raw materials that enter the kiln, the process parameters, and the end product of the calcination. Raman microspectroscopy combines high structural sensitivity with micrometre to sub-micrometre spatial resolution and compatibility with conventional thin-sectional samples in an almost unique fashion, making it an interesting complementary extension of the existing methodological arsenal for mortar analysis. Raman spectra are vibrational fingerprints of crystalline and amorphous compounds, and contain marker bands that are specific for minerals and their polymorphic forms. Relative intensities of bands that are related to the same crystalline species change according to crystal orientations, and band shifts can be caused by the incorporation of foreign ions into crystal lattices, as well as stoichiometric changes within solid solution series. Finally, variations in crystallinity affect band widths. These effects are demonstrated based on the analysis of three historical mortar samples: micrometric distribution maps of phases and polymorphs, crystal orientations, and compositional variations of solid solution series of unreacted clinker grains in the Portland cement mortars of two 19th century castings, and the crystallinities of thermal anhydrite clusters in a high-fired medieval gypsum mortar as a measure for the applied burning temperature were successfully acquired. KW - Cement clinker remnants KW - High-fired gypsum KW - Thermal anhydrite KW - Spectroscopic imaging KW - Raman microscopy PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515038 DO - https://doi.org/10.3390/heritage2020102 VL - 2 IS - 2 SP - 1662 EP - 1683 PB - MDPI CY - Basel AN - OPUS4-51503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmid, Thomas A1 - Dariz, P. T1 - Editorial for the special issue "Modern Raman spectroscopy of minerals" N2 - Raman spectroscopy provides vibrational fingerprints of chemical compounds enabling their unambiguous identification. The assignment of Raman spectra to minerals is straightforward, if appropriate reference data is accessible. Modern couplings of Raman spectroscopy with microscopy (Raman microspectroscopy) merge the high structural specificity with down to sub-micrometre spatial resolution. This analytical tool has high potential not only in the identification of minerals from natural sources but also for studying the complex microstructure and mineral distribution of both ancient and modern man-made materials. In addition to the chemical identity of minerals, Raman spectra are affected by crystal orientations (varying relative Raman band intensities); (sub)stoichiometric compositional changes (e.g., in solid solution series), traces of foreign ions, strain (the latter three shifting Raman bands); and crystallinity (changing Raman band widths), enabling a comprehensive physico-chemical characterisation of minerals. Thus, Raman spectroscopy – including its in situ measurement capabilities – provides possibilities to study mineral paragenesis in both, natural and man-made samples at the micrometre scale. While in 1928 the first experimental evidence for inelastic light scattering was provided by C. V. Raman and K. S. Krishnan by using sunlight for excitation, filters for selecting the inelastically scattered light, and their eyes for detection (later, photographic plates for acquisition of spectra were employed), modern Raman spectrometers make use of laser excitation, dispersive spectrographs and charge coupled device (CCD) detection. This Special Issue includes technological developments and applications in the field of modern Raman spectroscopy of minerals in a broad sense, from natural mineral deposits and archaeological objects to inorganic phases in man-made materials. The studied minerals include fossil resins, typical rock-forming minerals (calcite, quartz, forsterite), iron-sulphur species (e.g., mackinawite), a range of sulphates (gypsum, bassanite, anhydrite III, anhydrite II, celestine, barite, ternesite), as well as silicate minerals like garnets (e.g., almandine). KW - Raman spectroscopy KW - Raman microspectroscopy KW - Mineral identification KW - Physico-chemical characterisation of minerals KW - Mineral paragenesis PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515041 DO - https://doi.org/10.3390/min10100860 VL - 10 SP - 860 PB - MDPI CY - Basel AN - OPUS4-51504 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rietsch, P. A1 - Sobottka, S. A1 - Hoffmann, K. A1 - Popov, A. A. A1 - Hildebrandt, P. A1 - Sarkar, B. A1 - Resch-Genger, Ute A1 - Eigler, S. T1 - Between Aromatic and Quinoid Structure: A Symmetrical UV to Vis/NIR Benzothiadiazole Redox Switch N2 - Reversibly switching the light absorption of organic molecules by redox processes is of interest for applications in sensors, light harvesting, smart materials, and medical diagnostics. This work presents a symmetrical benzothiadiazole (BTD) derivative with a high fluorescence quantum yield in solution and in the crystalline state and shows by spectroelectrochemical analysis that reversible switching of UV absorption in the neutral state, to broadband Vis/NIR absorption in the 1st oxidized state, to sharp band Vis absorption in the 2nd oxidized state, is possible. For the one-electron oxidized species, formation of a delocalized radical is confirmed by electron paramagnetic resonance spectroelectrochemistry. Furthermore, our results reveal an increasing quinoidal distortion upon the 1st and 2nd oxidation, which can be used as the leitmotif for the development of BTD based redox switches. KW - Dye KW - Electrochemistry KW - Switch KW - Redox KW - Sensor KW - Photophysics KW - Quantum yield KW - photoluminescence PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517222 DO - https://doi.org/10.1002/chem.202004009 VL - 26 IS - 72 SP - 17361 EP - 17365 PB - Wiley-VCH GmbH AN - OPUS4-51722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Carl, F. A1 - Grauel, Bettina A1 - Pons, Monica A1 - Würth, Christian A1 - Haase, M. T1 - LiYF4:Yb/LiYF4 and LiYF4:Yb,Er/LiYF4 core/shell nanocrystals with luminescence decay times similar to YLF laser crystals and the upconversion quantum yield of the Yb,Er doped nanocrystals N2 - We developed a procedure to prepare luminescent LiYF4:Yb/LiYF4 and LiYF4:Yb,Er/LiYF4 core/shell nanocrystals with a size of approximately 40 nm revealing luminescence decay times of the dopant ions that approach those of high-quality laser crystals of LiYF4:Yb (Yb:YLF) and LiYF4:Yb,Er (Yb,Er:YLF) with identical doping concentrations. As the luminescence decay times of Yb3+ and Er3+ are known to be very sensitive to the presence of quenchers, the long decay times of the core/shell nanocrystals indicate a very low number of defects in the core particles and at the core/shell interfaces. This improvement in the performance was achieved by introducing two important modifications in the commonly used oleic acid based synthesis. First, the shell was prepared via anewly developed method characterized by a very low nucleation rate for particles of pure LiYF4 shell material. Second, anhydrous acetates were used as precursors and additional drying steps were applied to reduce the incorporation of OH− in the crystal lattice, known to quench the emission of Yb3+ ions. Excitation power density (P)-dependent absolute measurements of the upconversion luminescence quantum yield (Φ,UC) of LiYF4:Yb,Er/LiYF4 core/shell particles reveal a maximum value of 1.25% at P of 180 W·cm−2. Although lower than the values reported for NaYF4:18%Yb,2%Er core/shell nanocrystals with comparable sizes, these Φ, UC values are the highest reported so far for LiYF4:18%Yb,2%Er/LiYF4 nanocrystals without additional dopants. Further improvements May nevertheless be possible by optimizing the dopant concentrations in the LiYF4 nanocrystals. KW - Nano KW - Crystal KW - Quantum yield KW - LiYF4 KW - Synthesis KW - Lifetime KW - Fluorescence KW - NIR KW - Photoluminescence KW - Lanthanide KW - Upconversion nanoparticle KW - Nanomaterial PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515395 DO - https://doi.org/10.1007/s12274-020-3116-y SN - 1998-0124 VL - 14 IS - 3 SP - 797 EP - 806 PB - Springer AN - OPUS4-51539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kage, Daniel A1 - Hoffmann, Katrin A1 - Borcherding, H. A1 - Schedler, U. A1 - Resch-Genger, Ute T1 - Lifetime encoding in flow cytometry for bead‑based sensing of biomolecular interaction N2 - To demonstrate the potential of time-resolved flow cytometry (FCM) for bioanalysis, clinical diagnostics, and optically encoded bead-based assays, we performed a proof-of-principle study to detect biomolecular interactions utilizing fluorescence lifetime (LT)-encoded micron-sized polymer beads bearing target-specific bioligands and a recently developed prototype lifetime flow cytometer (LT-FCM setup). This instrument is equipped with a single excitation light source and different fluorescence detectors, one operated in the photon-counting mode for time-resolved measurements of fluorescence decays and three detectors for conventional intensity measurements in different spectral windows. First, discrimination of bead-bound biomolecules was demonstrated in the time domain exemplarily for two targets, Streptavidin (SAv) and the tumor marker human chorionic gonadotropin (HCG). In a second step, the determination of biomolecule concentration levels was addressed representatively for the inflammation-related biomarker tumor necrosis factor (TNF-α) utilizing fluorescence intensity measurements in a second channel of the LT-FCM instrument. Our results underline the applicability of LT-FCM in the time domain for measurements of biomolecular interactions in suspension assays. In the future, the combination of spectral and LT encoding and multiplexing and the expansion of the time scale from the lower nanosecond range to the longer nanosecond and the microsecond region is expected to provide many distinguishable codes. This enables an increasing degree of multiplexing which could be attractive for high throughput screening applications. KW - Fluorescence KW - Sensor KW - Assay KW - Protein KW - Multiplexing KW - Flow cytometry KW - Barcoding KW - Lifetime KW - Dye KW - Bead KW - Bead-based assay KW - Method KW - Quantification PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516007 DO - https://doi.org/10.1038/s41598-020-76150-x VL - 10 IS - 1 SP - 19477 PB - Nature AN - OPUS4-51600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bell, A. M. A1 - von der Au, Marcus A1 - Regnery, J. A1 - Schmid, M. A1 - Meermann, Björn A1 - Reifferscheid, G. A1 - Ternes, T. A1 - Buchinger, S. T1 - Does galvanic cathodic protection by aluminum anodes impact marine organisms? N2 - Background: Cathodic protection by sacrifcial anodes composed of aluminum-zinc-indium alloys is often applied to protect ofshore support structures of wind turbines from corrosion. Given the considerable growth of renewable energies and thus ofshore wind farms in Germany over the last decade, increasing levels of aluminum, Indium and zinc are released to the marine environment. Although these metals are ecotoxicologically well-studied, data regarding their impact on marine organisms, especially sediment-dwelling species, as well as possible ecotoxicological efects of galvanic anodes are scarce. To investigate possible ecotoxicological efects to the marine environment, the diatom Phaedactylum tricornutum, the bacterium Aliivibrio fscheri and the amphipod Corophium volutator were exposed to dissolved galvanic anodes and solutions of aluminum and zinc, respectively, in standardized laboratory tests using natural seawater. In addition to acute toxicological efects, the uptake of these elements by C. volutator was investigated. Results: The investigated anode material caused no acute toxicity to the tested bacteria and only weak but signifcant efects on algal growth. In case of the amphipods, the single elements Al and Zn showed signifcant efects only at the highest tested concentrations. Moreover, an accumulation of Al and In was observed in the crustacea species. Conclusions: Overall, the fndings of this study indicated no direct environmental impact on the tested marine organisms by the use of galvanic anodes for cathodic protection. However, the accumulation of metals in, e.g., crustaceans might enhance their trophic transfer within the marine food web. KW - Galvanic anodes KW - Metal toxicity KW - Metal uptake KW - Corophium volutator KW - Seawater PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520769 DO - https://doi.org/10.1186/s12302-020-00441-3 VL - 32 IS - 1 SP - Article number 157 AN - OPUS4-52076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rietsch, P. A1 - Sobottka, S. A1 - Hoffmann, Katrin A1 - Hildebrandt, P. A1 - Sarkar, B. A1 - Resch-Genger, Ute A1 - Eigler, S. T1 - Identification of the Irreversible Redox Behavior of Highly Fluorescent Benzothiadiazoles N2 - Redox switches are applied in various fields of research, including molecular lifts, electronic devices and sensors. Switching the absorbance between UV and Vis/NIR by redox processes is of interest for applications in light harvesting or biomedicine. Here, we present a series of push-pull benzothiadiazole derivatives with high fluorescence quantum yields in solution and in the crystalline solid state. Spectroelectrochemical analysis reveals the switching of UV-absorption in the neutral state to Vis/NIR absorption in the reduced state. We identify the partial irreversibility of the switching process, which appears to be reversible on the cyclic voltammetry timescale. KW - Redox switch KW - Electrochemistry KW - Dye KW - Fluorescence KW - Absorption KW - Sensor KW - Benzothiadiazole PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520865 DO - https://doi.org/10.1002/cptc.202000050 SN - 2367-0932 VL - 4 IS - 9 SP - 668 EP - 673 PB - Wiley Online Library AN - OPUS4-52086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Treiling, S. A1 - Wang, Cui A1 - Förster, C. A1 - Reichenauer, F. A1 - Kalmbach, J. A1 - Boden, P. A1 - Harris, J. P. A1 - Carrella, L. M. A1 - Rentschler, E. A1 - Resch-Genger, Ute A1 - Reber, C. A1 - Seitz, M. A1 - Gerhards, M. A1 - Heinze, K. T1 - Luminescence and Light-Driven Energy and Electron Transfer from an Exceptionally Long-Lived Excited State of a Non-Innocent Chromium(III) Complex N2 - Photoactive metal complexes employing Earth‐abundant metal ions are a key to sustainable photophysical and photochemical applications. We exploit the effects of an inversion center and ligand non‐innocence to tune the luminescence and photochemistry of the excited state of the [CrN6] chromophore [Cr(tpe)2]3+ with close to octahedral symmetry (tpe=1,1,1‐tris(pyrid‐2‐yl)ethane). [Cr(tpe)2]3+ exhibits the longest luminescence lifetime (τ=4500 μs) reported up to date for a molecular polypyridyl chromium(III) complex together with a very high luminescence quantum yield of Φ=8.2 % at room temperature in fluid solution. Furthermore, the tpe ligands in [Cr(tpe)2]3+ are redox non‐innocent, leading to reversible reductive chemistry. The excited state redox potential and lifetime of [Cr(tpe)2]3+ surpass those of the classical photosensitizer [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine) enabling energy transfer (to oxygen) and photoredox processes (with azulene and tri(n‐butyl)amine). KW - Quantum yield KW - Cr(III) complex KW - Longst luminescence lifetime KW - Electron transfer PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-494870 DO - https://doi.org/10.1002/anie.201909325 VL - 58 SP - 2 EP - 13 PB - Wiley-VCH AN - OPUS4-49487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nirmalananthan-Budau, Nithiya A1 - Rühle, Bastian A1 - Geißler, Daniel A1 - Moser, Marko A1 - Kläber, Christopher A1 - Schäfer, A. A1 - Resch-Genger, Ute T1 - Multimodal cleavable reporters for quantifying carboxy and amino groups on organic and inorganic nanoparticles N2 - Organic and inorganic nanoparticles (NPs) are increasingly used as drug carriers, fluorescent sensors, and multimodal labels in the life and material sciences. These applications require knowledge of the chemical nature, total number of surface groups, and the number of groups accessible for subsequent coupling of e.g., antifouling ligands, targeting bioligands, or sensor molecules. To establish the concept of catch-and-release assays, cleavable probes were rationally designed from a quantitatively cleavable disulfide moiety and the optically detectable reporter 2-thiopyridone (2-TP). For quantifying surface groups on nanomaterials, first, a set of monodisperse carboxy-and amino-functionalized, 100 nm-sized polymer and silica NPs with different surface group densities was synthesized. Subsequently, the accessible functional groups (FGs) were quantified via optical spectroscopy of the cleaved off reporter after its release in solution. Method validation was done with inductively coupled plasma optical emission spectroscopy (ICP-OES) utilizing the sulfur atom of the cleavable probe. This comparison underlined the reliability and versatility of our probes, which can be used for surface group quantification on all types of transparent, scattering, absorbing and/or fluorescent particles. The correlation between the total and accessible number of FGs quantified by conductometric titration, qNMR, and with our cleavable probes, together with the comparison to results of conjugation studies with differently sized biomolecules reveal the potential of catch-and-release reporters for surface analysis. Our findings also underline the importance of quantifying particularly the accessible amount of FGs for many applications of NPs in the life sciences. KW - Advanced Materials KW - Surface Chemistry KW - Organic–inorganic nanostructures KW - Funtional Groups KW - Quantitative Analysis PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-499081 DO - https://doi.org/10.1038/s41598-019-53773-3 VL - 9 SP - 17577-1 EP - 17577-11 PB - Springer Nature CY - London AN - OPUS4-49908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Büchele, Dominique A1 - Chao, Madlen A1 - Ostermann, Markus A1 - Leenen, M. A1 - Bald, Ilko T1 - Multivariate chemometrics as a key tool for prediction of K and Fe in a diverse German agricultural soil-set using EDXRF N2 - Within the framework of precision agriculture, the determination of various soil properties is moving into focus, especially the demand for sensors suitable for in-situ measurements. Energy-dispersive X-ray fluorescence (EDXRF) can be a powerful tool for this purpose. In this study a huge diverse soil set (n = 598) from 12 different study sites in Germany was analysed with EDXRF. First, a principal component analysis (PCA) was performed to identify possible similarities among the sample set. Clustering was observed within the four texture classes clay, loam, silt and sand, as clay samples contain high and sandy soils low iron mass fractions. Furthermore, the potential of uni- and multivariate data evaluation with partial least squares regression (PLSR) was assessed for accurate Determination of nutrients in German agricultural samples using two calibration sample sets. Potassium and iron were chosen for testing the performance of both models. Prediction of these nutrients in 598 German soil samples with EDXRF was more accurate using PLSR which is confirmed by a better overall averaged deviation and PLSR should therefore be preferred. KW - XRF KW - Chemometrics KW - Soil KW - Agriculture KW - Multivariate PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498671 DO - https://doi.org/10.1038/s41598-019-53426-5 VL - 9 SP - 17588 PB - Nature AN - OPUS4-49867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liu, H. A1 - Song, W. A1 - Gröninger, Delia A1 - Zhang, L. A1 - Lu, Y. A1 - Chan, K. S. A1 - Zhou, Z. A1 - Rurack, Knut A1 - Shen, Z. T1 - Real-time monitoring of newly acidified organelles during autophagy enabled by reaction-based BODIPY dyes N2 - Real-time monitoring of newly acidified organelles during autophagy in living cells is highly desirable for a better understanding of intracellular degradative processes. Herein, we describe a reaction-based boron dipyrromethene (BODIPY) dye containing strongly electron-withdrawing diethyl 2-cyanoacrylate groups at the α-positions. The probe exhibits intense red fluorescence in acidic organelles or the acidified cytosol while negligible fluorescence in other regions of the cell. The underlying mechanism is a nucleophilic reaction at the central meso-carbon of the indacene core, resulting in the loss of π-conjugation entailed by dramatic spectroscopic changes of more than 200 nm between its colorless, non-fluorescent leuco-BODIPY form and its red and brightly emitting form. The reversible transformation between red fluorescent BODIPY and leuco-BODIPY along with negligible cytotoxicity qualifies such dyes for rapid and direct intracellular lysosome imaging and cytosolic acidosis detection simultaneously without any washing step, enabling the real-time monitoring of newly acidified organelles during autophagy. KW - Autophagy KW - BODIPY KW - Fluorescence KW - Lysosome KW - Real-time imaging PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498358 UR - https://www.nature.com/articles/s42003-019-0682-1 DO - https://doi.org/10.1038/s42003-019-0682-1 SN - 23993642 VL - 2 SP - 442 PB - Nature Research CY - London AN - OPUS4-49835 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Silke A1 - Roethke, A. A1 - Rienitz, O. A1 - Matschat, Ralf A1 - Schiel, D. A1 - Jaehrling, R. A1 - Goerlitz, V. A1 - Kipphardt, Heinrich T1 - SI-traceable monoelemental solutions on the highest level of accuracy: 25 years from the foundation of CCQM to recent advances in the development of measurement methods N2 - Within the Working Group on Inorganic Analysis (IAWG) of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM) international key comparisons and pilot studies related to inorganic analysis are carried to ensure consistency in this field at the highest level. Some of these comparisons deal directly with the preparation and characterization of monoelemental solutions or with topics, closely related. The importance of monoelemental solutions lies in the fact that almost every measurement in inorganic analysis relies on the comparison with either a reference material, or references in form of solutions, usually (mono)elemental solutions. All quantitative measurement approaches, e.g. isotope dilution or standard addition, need an accurate reference solution made from a well characterized reference material, prepared under full gravimetric control. These primary (monoelemental) solutions do not only serve as arbitrary references/calibration solutions, but they also link up measurement results to the International System of units (SI), this way establishing the so-called metrological traceability to a measurement unit of the SI. Without such solutions on the highest possible level of accuracy and with the smallest possible associated uncertainties (for e.g. element content and/or impurities), an analysis itself can never be as good as it could be with appropriate reference solutions. This article highlights select key comparisons and pilot studies dealing with monoelemental solution related topics within the IAWG from the foundation of CCQM – 25 years ago – up to latest achievements in the field of inorganic analysis. KW - Metrology KW - SI Traceability KW - CCQM PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-496080 DO - https://doi.org/10.1088/1681-7575/ab5636 SN - 0026-1394 SN - 1681-7575 SP - 1 EP - 23 PB - IOP CY - Bristol AN - OPUS4-49608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmid, Thomas A1 - Dariz, P. ED - Ziemann, M. T1 - Raman band widths of anhydrite II reveal the burning history of high-fired medieval gypsum mortars N2 - The use of high-fired gypsum as binder for masonry and joint mortars or stuccowork in Central Europe in the Early and High Middle Ages was a regional specific as it depended on local gypsum deposits. The calcination technology possible at the time resulted in an assemblage of calcium sulphate phases dehydrated to different degrees and partly thermally damaged accessory minerals of the raw gypsum. Because of the absence of medieval textbooks, the observation of high-temperature, low-pressure mineral transformations and the correlation of phases coexisting in not hydrated binder relicts in the gypsum matrix to the mineralogy of the raw material and the burning conditions constitute the only source to the historical technological know-how. The CaSO4–H2O system consists of five crystalline phases, which can be discriminated by structural analysis methods, such as Raman spectroscopy, due to obvious differences in their spectroscopic data: gypsum (CaSO4 ⋅ 2 H2O), bassanite (hemihydrate, CaSO4 ⋅ ½ H2O), anhydrite III (CaSO4), anhydrite II (CaSO4), and anhydrite I (CaSO4). Only recently, it was possible to demonstrate that small spectroscopic variations exist also within the relatively large stability range of anhydrite II from approx. 180°C to 1180°C: all Raman bands narrow with increasing burning temperature applied in the synthesis from gypsum powder. The determination of band widths of down to 3 cm-1 and differences between them of a few tenths of a wavenumber is not a trivial task. Thus, this contribution discusses peak fitting and strategies for correction of instrument-dependent band broadening. Raman maps of polished thin sections of gypsum mortars provide access to the burning histories of individual remnant thermal anhydrite grains and enable the discrimination of natural anhydrite originating from the gypsum deposit. This novel analytical method was applied to samples from medieval South Tyrolean stucco decorations and sculptures. Beyond that, Raman microspectroscopy was employed for following pyrometamorphic reactions in natural impurities of the raw material. In the presented examples mineral thermometry indicates process temperatures above 800°C: the breakdown of magnesium-rich chlorite led to the formation of forsterite Mg2SiO4, while the thermal decomposition of dolomite CaMg(CO3)2 yielded – after hydration and carbonation – magnesite MgCO3, CaCO3 polymorphs and magnesian calcite. Lower burning temperatures, which leave the accessory minerals in their pristine form, can be traced by measuring the spectra of anhydrite crystalites in grains of firing products and evaluating Raman band widths. Throughout the applications of this analytical method so far, calcination temperatures ranging from approx. 600°C to 900°C were determined. T2 - 10th International Congress on the Application of Raman Spectroscopy in Art and Archaeology CY - Potsdam, Germany DA - 03.09.2019 KW - Raman microspectroscopy KW - High-fired medieval gypsum mortars KW - Raman band width KW - Gypsum dehydration KW - Thermal anhydrite PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-496204 SP - 36 EP - 37 PB - University of Potsdam CY - Potsdam AN - OPUS4-49620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Descalzo, Ana B. A1 - Ashokkumar, Pichandi A1 - Shen, Z. A1 - Rurack, Knut T1 - On the Aggregation Behaviour and Spectroscopic Properties of Alkylated and Annelated BoronDipyrromethene (BODIPY) Dyes in Aqueous Solution N2 - The tendency of boron-dipyrromethene (BODIPY) dyes to associate in water is well known, and usually a cause for inferior fluorescence properties. Synthetic efforts to chemically improve BODIPYs’ water solubility and minimize this problem have been numerous in the past. However, a deeper understanding of the phenomena responsible for fluorescence quenching is still required. Commonly, the spectroscopic behaviour in aqueous media has been attributed to aggregate or excimer formation, with such works often centring on a single BODIPY family. Herein, we provide an integrating discussion including very diverse types of BODIPY dyes. Our studies revealed that even subtle structural changes can distinctly affect the association behaviour of the fluorophores in water, involving different photophysical processes. The palette of behaviour found ranges from unperturbed emission, to the formation of H or J aggregates and excimers, to the involvement of tightly bound, preformed excimers. These results are a first step to a more generalized understanding of spectroscopic properties vs. structure, facilitating future molecular design of BODIPYs, especially as probes for biological applications. KW - Aggregates KW - BODIPY KW - Excimers KW - Fluorescence KW - Photophysics PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-497771 DO - https://doi.org/10.1002/cptc.201900235 SN - 2367-0932 VL - 4 IS - 2 SP - 120 EP - 131 PB - WILEY-VCH CY - Weinheim AN - OPUS4-49777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kembuan, C. A1 - Saleh, Maysoon I. A1 - Rühle, Bastian A1 - Resch-Genger, Ute A1 - Graf, C. T1 - Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness N2 - A concept for the growth of silica shells with a thickness of 5–250 nm onto oleate-coated NaYF4:Yb3+/Er3+ upconversion nanoparticles (UCNP) is presented. The concept enables the precise adjustment of shell thicknesses for the preparation of thick-shelled nanoparticles for applications in plasmonics and sensing. First, an initial 5–11 nm thick shell is grown onto the UCNPs in a reverse microemulsion. This is followed by a stepwise growth of these particles without a purification step, where in each step equal volumes of tetraethyl orthosilicate and ammonia water are added, while the volumes of cyclohexane and the surfactant Igepal® CO-520 are increased so that the ammonia water and surfactant concentrations remain constant. Hence, the number of micelles stays constant, and their size is increased to accommodate the growing core–shell particles. Consequently, the formation of core-free silica particles is suppressed. When the negative zeta potential of the particles, which continuously decreased during the stepwise growth, falls below −40 mV, the particles can be dispersed in an ammoniacal ethanol solution and grown further by the continuous addition of tetraethyl orthosilicate to a diameter larger than 500 nm. Due to the high colloidal stability, a coalescence of the particles can be suppressed, and single-core particles are obtained. This strategy can be easily transferred to other nanomaterials for the design of plasmonic nanoconstructs and sensor systems. KW - Reverse microemulsion KW - Silica coating KW - Stepwise growth KW - Thick shells KW - Upconversion nanoparticles PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502769 DO - https://doi.org/10.3762/bjnano.10.231 SN - 2190-4286 VL - 10 SP - 2410 EP - 2421 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, M. AN - OPUS4-50276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kage, Daniel A1 - Hoffmann, Katrin A1 - Nifontova, G. A1 - Krivenkov, V. A1 - Sukhanova, A. A1 - Nabiev, I. A1 - Resch-Genger, Ute T1 - Tempo-spectral multiplexing in flow cytometry with lifetime detection using QD-encoded polymer beads N2 - Semiconductor quantum dots (QDs) embedded into polymer microbeads are known to be very attractive emitters for spectral multiplexing and colour encoding. Their luminescence lifetimes or decay kinetics have been, however, rarely exploited as encoding parameter, although they cover time ranges which are not easily accessible with other luminophores. We demonstrate here the potential of QDs made from II/VI semiconductors with luminescence lifetimes of several 10 ns to expand the lifetime range of organic encoding luminophores in multiplexing applications using time-resolved flow cytometry (LT-FCM). For this purpose, two different types of QD-loaded beads were prepared and characterized by photoluminescence measurements on the ensemble level and by single-particle confocal laser scanning microscopy. Subsequently, these lifetime-encoded microbeads were combined with dye-encoded microparticles in systematic studies to demonstrate the potential of these QDs to increase the number of lifetime codes for lifetime multiplexing and combined multiplexing in the time and colour domain (tempo-spectral multiplexing). These studies were done with a recently developed novel luminescence lifetime flow cytometer (LT-FCM setup) operating in the time-domain, that presents an alternative to reports on phase-sensitive lifetime detection in flow cytometry. KW - Fluorescence life time KW - Flow cytometry KW - Lifetime-encoded beads KW - Quantum dots KW - Multiplexing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503316 DO - https://doi.org/10.1038/s41598-019-56938-2 VL - 10 IS - 1 SP - Article number: 653 PB - nature.com AN - OPUS4-50331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - von Boehn, B. A1 - Scholtz, Lena A1 - Imbihl, R. T1 - Reactivity and Stability of Ultrathin VOx Films on Pt(111) in Catalytic Methanol Oxidation N2 - The growth of ultrathin layers of VOx (<12 monolayers) on Pt(111) and the activity of these layers in catalytic methanol oxidation at 10−4 mbar have been studied with low-energy electron difraction, Auger electron spectroscopy, rate measurements, and with photoemission electron microscopy. Reactive deposition of V in O2 at 670 K obeys a Stranski–Krastanov growth mode with a (√3 × √3)R30° structure representing the limiting case for epitaxial growth of 3D-VOx. The activity of VOx/Pt(111) in catalytic methanol oxidation is very low and no redistribution dynamics is observed lifting the initial spatial homogeneity of the VOx layer. Under reaction conditions, part of the surface vanadium difuses into the Pt subsurface region. Exposure to O2 causes part of the V to difuse back to the surface, but only up to one monolayer of VOx can be stabilized in this way at 10−4 mbar. KW - Vanadium oxide catalysts KW - Pt(111) KW - Supported catalyst KW - Methanol oxidation KW - Stranski–Krastanow growth PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517376 DO - https://doi.org/10.1007/s11244-020-01321-z SN - 1022-5528 VL - 63 IS - 15-18 SP - 1545 EP - 1556 PB - Springer AN - OPUS4-51737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sun, C. A1 - Schäferling, Michael A1 - Resch-Genger, Ute A1 - Gradzielski, M. T1 - Solvothermal Synthesis of Lanthanide-doped NaYF4 Upconversion N2 - Lanthanide-doped NaYF4 upconversion nano- and microcrystals were synthesized via a facile solvothermal approach. Thereby, the influence of volume ratios of ethylene glycol (EG)/H2O, molar ratios of NH4F/RE3+ (RE3+ represents the total amount of Y3+ and rare-earth dopant ions), Gd3+ ion contents, types of activator dopant ions, and different organic co-solvents on the crystal phase, size, and morphology of the resulting particles were studied systematically. A possible formation mechanism for the growth of crystals of different morphology is discussed. Our results show that the transition from the α- to the β-phase mainly depends on the volume ratio of EG/H2O and the molar ratio of NH4F/RE3+, while the morphology and size could be controlled by the type of organic co-solvent and Gd3+ dopant ions. Furthermore, the reaction time has to be long enough to convert α-NaYF4 into β-NaYF4 during the growth process to optimize the upconversion luminescence. The formation of larger β-NaYF4 crystals, which possess a higher upconversion luminescence than smaller particles, proceeds via intermediates of smaller crystals of cubic structure. In summary, our synthetic approach presents a facile route to tailor the size, Crystal phase, morphology, and luminescence features of upconversion materials. KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Photoluminescence KW - Lanthanide KW - Quantum yield KW - Photophysics KW - Lifetime KW - Surface chemistry KW - Single particle KW - Brightness KW - NIR KW - Synthesis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520307 DO - https://doi.org/10.1002/cnma.202000564 VL - 7 IS - 2 SP - 174 EP - 183 PB - Wiley AN - OPUS4-52030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, A. A1 - Lischeid, G. A1 - Koch, Matthias A1 - Lentzsch, P. A1 - Sommerfeld, Thomas A1 - Müller, M.H. T1 - Co-Cultivation of Fusarium, Alternaria, and Pseudomonas on Wheat-Ears Affects Microbial Growth and Mycotoxin Production N2 - Mycotoxigenic fungal pathogens Fusarium and Alternaria are a leading cause of loss in cereal production. On wheat-ears, they are confronted by bacterial antagonists such as pseudomonads. Studies on these groups’ interactions often neglect the infection process’s temporal aspects and the associated priority effects. In the present study, the focus was on how the first colonizer affects the subsequent ones. In a climate chamber experiment, wheat-ears were successively inoculated with two different strains (Alternaria enuissima At625, Fusarium graminearum Fg23, or Pseudomonas simiae Ps9). Over three weeks, microbial abundances and mycotoxin concentrations were analyzed and visualized via Self Organizing Maps with Sammon Mapping (SOM-SM). All three strains revealed different characteristics and strategies to deal with co-inoculation: Fg23, as the first colonizer, suppressed the establishment of At625 and Ps9. Nevertheless, primary inoculation of At625 reduced all of the Fusarium toxins and stopped Ps9 from establishing. Ps9 showed priority effects in delaying and blocking the production of the fungal mycotoxins. The SOM-SM analysis visualized the competitive strengths: Fg23 ranked first, At625 second, Ps9 third. Our findings of species-specific priority effects in a natural environment and the role of the mycotoxins involved are relevant for developing biocontrol strategies. KW - Antagonists KW - Microbe interactions KW - Mycotoxins KW - Priority effect KW - SOM-SM PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521554 DO - https://doi.org/10.3390/microorganisms9020443 VL - 9 IS - 2 SP - 443 PB - MDPI AN - OPUS4-52155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lange, M. A. A1 - Khan, I. A1 - Opitz, P. A1 - Hartmann, J: A1 - Ashraf, M. A1 - Qurashi, A. A1 - Prädel, L. A1 - Panthöfer, M. A1 - Cossmer, Antje A1 - Pfeifer, Jens A1 - Simon, Fabian A1 - von der Au, Marcus A1 - Meermann, Björn A1 - Mondeshki, M. A1 - Tahir, M. N. A1 - Tremel, W. T1 - A Generalized Method for High-Speed Fluorination of Metal Oxides by Spark Plasma Sintering Yields Ta3O7F and TaO2F with High Photocatalytic Activity for Oxygen Evolution from Water N2 - A general method to carry out the fluorination of metal oxides with poly(tetrafluoroethylene) (PTFE, Teflon) waste by spark plasma sintering (SPS) on a minute scale with Teflon is reported. The potential of this new approach is highlighted by the following results. i) The tantalum oxyfluorides Ta3O7F and TaO2F are obtained from plastic scrap without using toxic or caustic chemicals for fluorination. ii) Short reaction times (minutes rather than days) reduce the process time the energy costs by almost three orders of magnitude. iii) The oxyfluorides Ta3O7F and TaO2F are produced in gram amounts of nanoparticles. Their synthesis can be upscaled to the kg range with industrial sintering equipment. iv) SPS processing changes the catalytic properties: while conventionally prepared Ta3O7F and TaO2F show little catalytic activity, SPS-prepared Ta3O7F and TaO2F exhibit high activity for photocatalytic oxygen evolution, reaching photoconversion efficiencies up to 24.7% and applied bias to photoconversion values of 0.86%. This study shows that the materials properties are dictated by the processing which poses new challenges to understand and predict the underlying factors. KW - Fluorination KW - Oxygen evolution reaction KW - Photocatalysis KW - Spark plasma sintering KW - Tantalum oxyfluorides PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524329 DO - https://doi.org/10.1002/adma.202007434 VL - 23 IS - 20 SP - 7434 PB - Wiley‐VCH GmbH AN - OPUS4-52432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hernandez-Castillo, A. O. A1 - Bischoff, J. A1 - Lee, J. H. A1 - Langenhan, Jennifer A1 - Karra, M. A1 - Meijer, G. A1 - Eibenberger-Arias, S. T1 - High-resolution UV spectroscopy of 1-indanol N2 - We report on rotationally resolved laser induced fluorescence (LIF) and vibrationally resolved resonanceenhanced multiphoton ionization (REMPI) spectroscopy of the chiral molecule 1-indanol. Spectra of the S1 ’ S0 electronic transition are recorded in a jet-cooled, pulsed molecular beam. Using two timedelayed pulsed lasers, the lifetimes of the S1 state of the two most stable conformers, referred to as eq1 and ax2, have been determined. The S1 ’ S0 origin bands of these conformers as well as the Transition to a vibrationally excited level in the S1 state of eq1 are recorded with full rotational resolution (25 MHz observed linewidth) by measuring the LIF intensity following excitation with a tuneable, narrowband cw laser. On selected rotationally resolved electronic transitions, Lamb-dips are measured to confirm the Lorentzian lifetime-contribution to the observed lineshapes. The rotationally resolved S1 ’ S0 origin band of a neon-complex of eq1 is measured via LIF as well. The fit of the rotationally resolved LIF spectra of the origin bands to those of an asymmetric rotor yields a standard deviation of about 6 MHz. The resulting spectroscopic parameters are tabulated and compared to the outcome of ab initio calculations. For both conformers as well as for the Ne-eq1 complex, the geometric structures in the S0 and S1 states are discussed. For all systems, the transition dipole moment is mainly along the a-axis, the contributions along the b- and c-axes being about one order of magnitude smaller. KW - REMPI KW - LIF KW - 1-indanol PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525056 DO - https://doi.org/10.1039/d0cp06170k VL - 23 IS - 12 SP - 7048 EP - 7056 PB - Royal Society of Chemistry AN - OPUS4-52505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kimani, Martha Wamaitha A1 - Beyer, S. A1 - El-Schich, Z. A1 - Gawlitza, Kornelia A1 - Rurack, Knut A1 - Gjörloff-Wingren, A. T1 - Imprinted Particles for Direct Fluorescence Detection of Sialic Acid in Polar Media and on Cancer Cells with Enhanced Control of Nonspecific Binding N2 - Glycoproteins are abundant on the cell surface of mammals, providing structural support, modulating cell Membrane properties, and acting as signaling agents. Variation of glycosylation patterns has been found to indicate various disease states, including cell malignancy. Sialic acid (SA) is present as a terminating group on cell-surface glycans, and its overexpression has been linked to several types of cancer. Detection of SA on the cell surface is therefore critical for detection of cancer in its early stages. In this work, a fluorescent molecularly imprinted polymer layer targeting SA was synthesized on the surface of silica-coated polystyrene (PS) particles. Compared to previous works, a PS core supplies a lighter, lower-density support for improved suspension stability and scattering properties. Moreover, their smaller size provides a higher surface-area-to-volume ratio for binding. The incorporation of a fluorescent monomer in the MIP shell allowed for simple and rapid determination of binding specificity in polar media due to a deprotonation−reprotonation interaction mechanism between the fluorescent monomer and SA, which led to spectral changes. Upon titration of the MIP particles with SA in suspension, an increase in fluorescence emission of the particles was observed, with the MIP particles binding SA more selectively compared to the nonimprinted polymer (NIP) control particles. In cell staining experiments performed by flow cytometry, the binding behavior of the MIP particles compared favorably with that of SA-binding lectins. NIPs prepared with a “dummy” template served as a better negative control in cell binding assays due to the favorable inward orientation of template-binding functional groups in the polymer shell, which reduced nonspecific binding. The results show that fluorescent MIPs targeting SA are a promising tool for in vitro fluorescence staining of cancerous cells and for future diagnosis of cancer at early stages. KW - Flow cytometry KW - Sialic acid KW - Fluorescence KW - Molecularly imprinted polymers KW - Cancer cells PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525216 DO - https://doi.org/10.1021/acsapm.0c01353 VL - 3 IS - 5 SP - 2363 EP - 2373 PB - American Chemical Society AN - OPUS4-52521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maisuls, I. A1 - Wang, Cui A1 - Gutierrez Suburu, M. E. A1 - Wilde, S. A1 - Daniliuc, C.-G. A1 - Brunink, D. A1 - Doltsinis, N. L. A1 - Ostendorp, S. A1 - Kösters, J. A1 - Resch-Genger, Ute A1 - Strassert, C. A. T1 - Ligand-controlled and nanoconfinement-boosted luminescence employing Pt(II) and Pd(II) complexes: from color-tunable aggregation-enhanced dual emitters towards self-referenced oxygen reporters N2 - In this work, we describe the synthesis, structural and photophysical characterization of four novel Pd(II) and Pt(II) complexes bearing tetradentate luminophoric ligands with high photoluminescence quantum yields (FL) and long excited state lifetimes (s) at room temperature, where the results were interpreted by means of DFT calculations. Incorporation of fluorine atoms into the tetradentate ligand favors aggregation and thereby, a shortened average distance between the metal centers, which provides accessibility to metal–metal-to-ligand charge-transfer (3MMLCT) excimers acting as red-shifted Energy traps if compared with the monomeric entities. This supramolecular approach provides an elegant way to enable room-temperature phosphorescence from Pd(II) complexes, which are otherwise quenched by a thermal population of dissociative states due to a lower ligand field splitting. Encapsulation of These complexes in 100 nm-sized aminated polystyrene nanoparticles enables concentration-controlled aggregation-enhanced dual emission. This phenomenon facilitates the tunability of the absorption and emission colors while providing a rigidified environment supporting an enhanced FL up to about 80% and extended s exceeding 100 ms. Additionally, these nanoarrays constitute rare examples for selfreferenced oxygen reporters, since the phosphorescence of the aggregates is insensitive to external influences, whereas the monomeric species drop in luminescence lifetime and intensity with increasing triplet molecular dioxygen concentrations (diffusion-controlled quenching). KW - Fluorescence KW - Multiplexing KW - Lifetime KW - Bead KW - Particle KW - Dye KW - Barcoding KW - Encoding KW - Quantum yield KW - Label KW - Reporter KW - Pd(II) KW - Pt(II) KW - Complex KW - NMR KW - X-ray KW - Sythesis KW - Aggregation KW - Monomer KW - Color PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525288 DO - https://doi.org/10.1039/d0sc06126c VL - 12 IS - 9 SP - 3270 EP - 3281 PB - Royal Society of Chemistry AN - OPUS4-52528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Alnajjar, M. A. A1 - Bartelmeß, Jürgen A1 - Hein, R. A1 - Ashokkumar, Pichandi A1 - Nilam, M. A1 - Nau, W. M. A1 - Rurack, Knut A1 - Hennig, A. T1 - Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril N2 - We introduce herein boron-dipyrromethene (BODIPY) dyes as a new class of fluorophores for the design of reporter dyes for supramolecular host–guest complex formation with cucurbit[7]uril (CB7). The BODIPYs contain a protonatable aniline nitrogen in the meso-position of the BODIPY chromophore, which was functionalized with known binding motifs for CB7. The unprotonated dyes show low fluorescence due to photoinduced electron transfer (PET), whereas the protonated dyes are highly fluorescent. Encapsulation of the binding motif inside CB7 positions the aniline nitrogen at the carbonyl rim of CB7, which affects the pKa value, and leads to a host-induced protonation and thus to a fluorescence increase. The possibility to tune binding affinities and pKa values is demonstrated and it is shown that, in combination with the beneficial photophysical properties of BODIPYs, several new applications of host–dye reporter pairs can be implemented. This includes indicator displacement assays with favourable absorption and emission wavelengths in the visible spectral region, fluorescence correlation spectroscopy, and noncovalent surface functionalization with fluorophores. KW - BODIPY KW - Cucurbituril KW - Fluorescence KW - PH KW - Photoinduced Electron Transfer KW - Supramolecular Chemistry PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-456361 UR - https://www.beilstein-journals.org/bjoc/content/pdf/1860-5397-14-171.pdf DO - https://doi.org/10.3762/bjoc.14.171 SN - 1860-5397 VL - 14 SP - 1961 EP - 1971 PB - Beilstein-Institut CY - Frankfurt a. M. AN - OPUS4-45636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kage, Daniel A1 - Hoffmann, Katrin A1 - Wittkamp, M. A1 - Ameskamp, J. A1 - Göhde, W. A1 - Resch-Genger, Ute T1 - Luminescence lifetime encoding in time-domain flow cytometry N2 - Time-resolved flow cytometry represents an alternative to commonly applied spectral or intensity multiplexing in bioanalytics. At present, the vast majority of the reports on this topic focuses on phase-domain techniques and specific applications. In this report, we present a flow cytometry platform with time-resolved detection based on a compact setup and straightforward time-Domain measurements utilizing lifetime-encoded beads with lifetimes in the nanosecond range. We provide general assessment of time-domain flow cytometry and discuss the concept of this platform to address achievable resolution limits, data analysis, and requirements on suitable encoding dyes. Experimental data are complemented by numerical calculations on photon count numbers and impact of noise and measurement time on the obtained lifetime values. KW - Flow cytometry KW - Fluorescence KW - Life sciences KW - Lifetime encoding KW - Polymer particles PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-465765 DO - https://doi.org/10.1038/s41598-018-35137-5 SN - 2045-2322 VL - 8 IS - 1 SP - 16715, 1 EP - 11 PB - Nature CY - London AN - OPUS4-46576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keller, Julia A1 - Moldenhauer, Daniel A1 - Byrne, L. A1 - Haase, H. A1 - Resch-Genger, Ute A1 - Koch, Matthias T1 - Complexes of the mycotoxins citrinin and ochratoxin A with aluminum ions and their spectroscopic properties N2 - The sensitive detection of the mycotoxin citrinin (CIT) utilizing ist fluorescence requires approaches to enhance the emission. In this respect, we studied the complexation of CIT and ochratoxin A (OTA) with Al3+ in methanol using absorption and fluorescence spectroscopy. In this context, an isocratic high performance liquid chromatography (HPLC) method using a polymer column and a fluorescence detector was also developed that enables the separation of the metal ion complexes from the free ligands and non-complexed Al3+. CIT and OTA showed distinct changes in their absorption and fluorescence properties upon Al3+-coordination, and the fluorescence of CIT was considerably enhanced. Analysis of the photometrically assessed titration of CIT and OTA with Al3+ using the Job plot method revealed 1:2 and 1:1 stoichiometries for the Al3+ complexes of CIT (Al:CIT) and OTA (Al:OTA), respectively. In the case of CIT, only one -diketone moiety participates in Al3+ coordination. These findings can be elegantly exploited for signal amplification and provide the base to reduce the limit of detection for CIT quantification by about an order of magnitude, as revealed by HPLC measurements using a fluorescence detector. KW - Complexation KW - Aluminum KW - Fluorescence KW - Job plot KW - HPLC-DAD/FLD PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-470502 DO - https://doi.org/10.3390/toxins10120538 SN - 2072-6651 VL - 10 IS - 12 SP - 538, 1 EP - 8 PB - MDPI CY - Basel AN - OPUS4-47050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Hecht, Mandy A1 - Witthuhn, Heike A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Cover profile for the article "Mix‐&‐read determination of Mercury(II) at trace levels with hybrid mesoporous silica materials incorporating fluorescent probes by a simple mix‐&‐load technique" N2 - Invited for this month’s cover picture is the group of Dr. Knut Rurack at the Department of Analytical Chemistry; Reference Materials at the Bundesanstalt fuer Materialforschung und -pruefung (BAM) in Berlin (Germany). The cover picture shows how differences in color and fluorescence on a test strip can be easily read out with a mobile device. Two reference spots Frame the sensitive spot that indicates the presence of trace amounts of HgII below the threshold in a natural water sample. This dipstick contains a hybrid material that combines boron-dipyrromethene (BODIPY) probes sterically loaded into specifically tailored mesoporous silica particles, allowing for ultrasensitive HgII detection through enhanced fluorescence in a few seconds. The applicability in real water samples and fish extracts are also studied. KW - Mercury KW - Fluorescence KW - Dip-stick assay KW - Group profile PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471267 DO - https://doi.org/10.1002/open.201800231 SN - 2191-1363 VL - 7 IS - 12 SP - 932 EP - 933 PB - Wiley-VCH CY - Weinheim AN - OPUS4-47126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El-Khatib, A. H. A1 - Radbruch, H. A1 - Trog, S. A1 - Neumann, B. A1 - Paul, F. A1 - Koch, A. A1 - Linscheid, M. W. A1 - Jakubowski, Norbert A1 - Schellenberger, E. T1 - Gadolinium in human brain sections and colocalization with other elements N2 - Recent recommendations by the Food and Drug Administration1 and the European Medicines Agency2 are to limit the clinical use of linear gadolinium-based contrast agents (GBCAs) due to convincing evidence of deposition in tissues. Macrocyclic GBCA continued to be considered safe, provided that patients have normal renal function. To date, given the low sensitivity of conventional MRI, there has been a debate about the signal increase following the injections of a macrocyclic GBCA. KW - Gadolinium PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471309 DO - https://doi.org/10.1212/NXI.0000000000000515 SN - 2332-7812 VL - 6 IS - 1 SP - e515, 1 EP - 3 PB - American Academy of Neurology AN - OPUS4-47130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Duewer, D. L. A1 - Murray, J. A. A1 - Wood, L. J. A1 - Wise, S. A. A1 - Hein, Sebastian A1 - Koch, Matthias A1 - Philipp, Rosemarie A1 - Werneburg, Martina A1 - Hackenberg, R. A1 - Polzer, J. A1 - Avila, M. A. A1 - Serrano, V. A1 - Kakoulides, E. A1 - Alexopoulos, C. A1 - Giannikopoulou, P. A1 - Gui, E. M. A1 - Lu, T. A1 - Teo, T. L. A1 - Hua, T. A1 - Dazhou, C. A1 - Chunxin, L. A1 - Changjun, Y. A1 - Hongmei, L. A1 - Nammoonnoy, J. A1 - Sander, L. C. A1 - Lippa, K. A1 - Quinn, L. A1 - Swiegelaar, C. A1 - Fernandes-Whaley, M. A1 - Gören, A. C. A1 - Gökcen, T. T1 - CCQM-K95.1 Low-polarity analytes in a botanical matrix: Polycyclic aromatic hydrocarbons (PAHs) in tea N2 - Extraction, chromatographic separation, and quantification of low-concentration organic compounds in complex matrices are core challenges for reference material producers and providers of calibration services. Evidence of successful participation in formal, relevant international comparisons is needed to document measurement capability claims made by national metrology institutes (NMIs) and designated institutes (DIs). To enable NMIs and DIs to update or establish their claims, in 2014 the Organic Analysis Working Group (OAWG) initiated CCQM-K95.1 "Low-Polarity Analytes in a Botanical Matrix: Polycyclic Aromatic Hydrocarbons (PAHs) in Tea". This was a follow-on comparison from CCQM-K95 which was completed in 2014. The polycyclic aromatic hydrocarbons (PAHs) benz[a]anthracene (BaA) and benzo[a]pyrene (BaP) are considered priority pollutants by U.S. Environmental Protection Agency and are regulated contaminants in food, pose chromatographic separation challenges, and for which exist well-characterized measurement procedures and standard materials. BaA and BaP in a smoked tea were therefore selected as representative target measurands for CCQM-K95.1. Ten NMIs participated in CCQM-K95.1. The consensus summary mass fractions for the two PAHs are in the range of (50 to 70) ng/g with relative standard deviations of (6 to 10) %. Successful participation in CCQM K95.1 demonstrates the following measurement capabilities in determining mass fraction of organic compounds, with molar mass of 100 g/mol to 500 g/mol and having polarity pKow −2, in a botanical matrix ranging in mass fraction from 10 ng/g to 1000 ng/g: (1) value assignment of primary reference standards (if in-house purity assessment carried out), (2) value assignment of single and/or multi-component organic solutions, (3) extraction of analytes of interest from the matrix, (4) cleanup and separation of analytes of interest from interfering matrix or extract components, and (5) separation and quantification using gas chromatography or liquid chromatography. KW - Benz[a]anthracene (BaA) KW - Benzo[a]pyrene (BaP) KW - Gas chromatography (GC) KW - Isotope dilution (ID) KW - Liquid chromatography (LC) KW - Mass spectrometry (MS) KW - Polycyclic aromatic hydrocarbon (PAH) KW - Yerba mate tea PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471430 DO - https://doi.org/10.1088/0026-1394/56/1A/08002 SN - 0026-1394 SN - 1681-7575 VL - 56 IS - 1 A SP - 08002, 1 EP - 89 PB - IOP Science AN - OPUS4-47143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Duewer, D. L. A1 - Sander, L. C. A1 - Wise, S. A. A1 - Philipp, Rosemarie A1 - Hein, Sebastian A1 - Hackenberg, R. A1 - Polzer, J. A1 - Avila, M. A. A1 - Serrano, V. A1 - Kakoulides, E. A1 - Alexopoulos, C. A1 - Giannikopoulou, P. A1 - Chan, P. A1 - Lee, H. A1 - Tang, H. A1 - Tang, P. A1 - Yip, Y. A1 - Lu, T. A1 - Cheow, P. S. A1 - Teo, T. L. A1 - Sega, M. A1 - Rolle, F. A1 - Baek, S. A1 - Kim, B. A1 - Lee, S. A1 - Cabillic, J. A1 - Fallot, C. A1 - Hua, T. A1 - Dazhou, C. A1 - Changjun, Y. A1 - Chunxin, L. A1 - Hongmei, L. A1 - Lippa, K. A1 - Itoh, N. A1 - Quinn, L. A1 - Prevoo-Franzsen, D. A1 - Fernandes-Whaley, M. A1 - Gören, A. C. A1 - Gökcen, T. A1 - Gündüz, S. A1 - Krylov, A. A1 - Mikheeva, A. A1 - Baldan, A. A1 - van der Hout, J. W. A1 - van der Veen, A. M. H. T1 - CCQM-K131 Low-polarity analytes in a multicomponent organic solution: Polycyclic aromatic hydrocarbons (PAHs) in acetonitrile N2 - Solutions of organic analytes of known mass fraction are typically used to calibrate the measurement processes used to determine these compounds in matrix samples. Appropriate value assignments and uncertainty calculations for calibration solutions are critical for accurate measurements. Evidence of successful participation in formal, relevant international comparisons is needed to document measurement capability claims (CMCs) made by national metrology institutes (NMIs) and designated institutes (DIs). To enable NMIs and DIs to update or establish their claims, in 2015 the Organic Analysis Working Group (OAWG) sponsored CCQM-K131 "Low-Polarity Analytes in a Multicomponent Organic Solution: Polycyclic Aromatic Hydrocarbons (PAHs) in Acetonitrile". Polycyclic aromatic hydrocarbons (PAHs) result from combustion sources and are ubiquitous in environmental samples. The PAH congeners, benz[a]anthracene (BaA), benzo[a]pyrene (BaP), and naphthalene (Nap) were selected as the target analytes for CCQM-K131. These targets span the volatility range of PAHs found in environmental samples and include potentially problematic chromatographic separations. Nineteen NMIs participated in CCQM-K131. The consensus summary mass fractions for the three PAHs are in the range of (5 to 25) μg/g with relative standard deviations of (2.5 to 3.5) %. Successful participation in CCQM-K131 demonstrates the following measurement capabilities in determining mass fraction of organic compounds of moderate to insignificant volatility, molar mass of 100 g/mol up to 500 g/mol, and polarity pKow < −2 in a multicomponent organic solution ranging in mass fraction from 100 ng/g to 100 μg/g: (1) value assignment of primary reference standards (if in-house purity assessment carried out), (2) value assignment of single and/or multi-component organic solutions, and (3) separation and quantification using gas chromatography or liquid chromatography. KW - Benz[a]anthracene (BaA) KW - Benzo[a]pyrene (BaP) KW - Gas chromatography (GC) KW - Isotope dilution (ID) KW - Liquid chromatography (LC) KW - Mass spectrometry (MS) KW - Naphthalene (Nap) KW - Organic calibration solution KW - Polycyclic aromatic hydrocarbon (PAH) PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471442 DO - https://doi.org/10.1088/0026-1394/56/1A/08003 SN - 0026-1394 SN - 1681-7575 VL - 56 IS - 1A SP - 08003, 1 EP - 102 PB - IOP Science AN - OPUS4-47144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ren, J. A1 - Weigert, Florian A1 - Weber, F. A1 - Wang, Y. A1 - Choudhury, S. A1 - Xiao, J. A1 - Lauermann, I. A1 - Resch-Genger, Ute A1 - Bande, A. A1 - Petit, T. ED - Petit, Tristan T1 - Influence of surface chemistry on optical, chemical and electronic properties of blue luminescent carbon dots N2 - Carbon dots have attracted much attention due to their unique optical, chemical and electronic properties enabling a wide range of applications. The properties of carbon dots can be effectively adjusted through modifying their chemical composition. However, a major challenge remains in understanding the core and surface contributions to optical and electronic transitions. Here, three blue luminescent carbon dots with carboxyl, amino and hydroxyl groups were comprehensively characterized by UV-vis absorption and emission spectroscopy, synchrotron-based X-ray spectroscopy, and infrared spectroscopy. The influence of the surface functionality on their fluorescence was probed by pH-dependent photoluminescence measurements. Moreover, the hydrogen bonding interactions between water and the surface groups of carbon dots were characterized by infrared spectroscopy. Our results show that both core and surface electronic states of blue luminescent carbon dots contribute to electronic acceptor levels while the chemical nature of the surface groups determines the hydrogen bonding behavior of the carbon dots. This comprehensive spectroscopic study demonstrates that the surface chemistry has a profound influence on the electronic configuration and surface–water interaction of carbon dots, thus affecting their photoluminescence properties. KW - Quantum dots KW - Spectroscopy KW - UV Vis KW - Fluorescence KW - Surface chemistry PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-472325 DO - https://doi.org/10.1039/c8nr08595a SN - 2040-3372 VL - 11 IS - 4 SP - 2056 EP - 2064 PB - RSC AN - OPUS4-47232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Saleh, Maysoon I. A1 - Panas, I. A1 - Frenzel, Florian A1 - Würth, Christian A1 - Rühle, Bastian A1 - Slominskii, Y. A1 - Demchenko, A. A1 - Resch-Genger, Ute T1 - Sensitization of upconverting nanoparticles with a NIR-emissive cyanine dye using a micellar encapsulation approach N2 - Photon upconversion nanomaterials have a wide range of applications, including biosensing and deep-tissue imaging. Their typically very weak and narrow absorption bands together with their size dependent luminescence efficiency can limit their application potential. This has been addressed by increasingly sophisticated core-shell particle architectures including the sensitization with organic dyes that strongly absorb in the near infrared (NIR). In this work, we present a simple water-dispersible micellar system that features energy transfer from the novel NIR excitable dye, 1859 SL with a high molar absorption coefficient and a moderate fluorescence quantum yield to oleate-capped NaYF4:20%Yb(III), 2%Er(III) upconversion nanoparticles (UCNP) upon 808 nm excitation. The micelles were formed using the surfactants Pluronic F-127 and Tween 80 to produce a hydrophilic dye-UCNP system. Successful energy transfer from the dye to the UCNP could be confirmed by emission measurements that revealed the occurrence of upconversion emission upon excitation at 808 nm and an enhancement of the green Er(III) emission compared to direct Er(III) excitation at 808 nm. KW - Upconversion nanoparticles KW - Sensitization KW - NIR dyes KW - Energy transfer PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-472300 DO - https://doi.org/10.1088/2050-6120/aafe1f SN - 2050-6120 VL - 7 IS - 1 (Special issue: Upconversion Methods, Applications and Materials) SP - 014003-1 EP - 014003-9 PB - IOP AN - OPUS4-47230 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yadav, Anur A1 - Iost, R. M. A1 - Neubert, T. J. A1 - Baylan, S. A1 - Schmid, Thomas A1 - Balasubramanian, Kannan T1 - Selective electrochemical functionalization of the graphene edge N2 - We present a versatile and simple method using electrochemistry for the exclusive functionalization of the edge of a graphene monolayer with metal nanoparticles or polymeric amino groups. The attachment of metal nanoparticles allows us to exploit surface-enhanced Raman scattering to characterize the chemistry of both the pristine and the functionalized graphene edge. For the pristine patterned graphene edge, we observe the typical edge-related modes, while for the functionalized graphene edge we identify the chemical structure of the functional layer by vibrational fingerprinting. The ability to obtain single selectively functionalized graphene edges routinely on an insulating substrate opens an avenue for exploring the effect of edge chemistry on graphene properties systematically. KW - Graphene KW - Nanoparticles KW - Nanosciences KW - Surface-enhanced Raman scattering KW - Atomic force microscopy PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-474357 DO - https://doi.org/10.1039/C8SC04083D SN - 2041-6520 VL - 10 IS - 3 SP - 936 EP - 942 PB - Royal Society of Chemistry AN - OPUS4-47435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zeise, I. A1 - Heiner, Z. A1 - Holz, S. A1 - Joester, Maike A1 - Buttner, C. A1 - Kneipp, Janina T1 - Raman imaging of plant cell walls in sections of cucumis sativus N2 - Raman microspectra combine information on chemical composition of plant tissues with spatial information. The contributions from the building blocks of the cell walls in the Raman spectra of plant tissues can vary in the microscopic sub-structures of the tissue. Here, we discuss the analysis of 55 Raman maps of root, stem, and leaf tissues of Cucumis sativus, using different spectral contributions from cellulose and lignin in both univariate and multivariate imaging methods. Imaging based on hierarchical cluster analysis (HCA) and principal component analysis (PCA) indicates different substructures in the xylem cell walls of the different tissues. Using specific signals from the cell wall spectra, analysis of the whole set of different tissue sections based on the Raman images reveals differences in xylem tissue morphology. Due to the specifics of excitation of the Raman spectra in the visible wavelength range (532 nm), which is, e.g., in resonance with carotenoid species, effects of photobleaching and the possibility of exploiting depletion difference spectra for molecular characterization in Raman imaging of plants are discussed. The reported results provide both, specific information on the molecular composition of cucumber tissue Raman spectra, and general directions for future imaging studies in plant tissues. KW - Raman KW - Imaging KW - Pants PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-474610 DO - https://doi.org/10.3390/plants7010007 SN - 2223-7747 VL - 7 IS - 1 SP - 7, 1 EP - 16 PB - MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND AN - OPUS4-47461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -