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 - CONF A1 - Steglich, P. A1 - Mai, C. A1 - Bondarenko, S. A1 - Paul, Martin A1 - Weller, Michael G. A1 - Schrader, S. A1 - Mai, A. T1 - BioPIC - Integration of Biosensors based on Photonic Integrated Circuits by Local-Backside Etching N2 - Silicon photonic sensors are promising candidates for lab-on-a-chip solutions with versatile applications and scalable production prospects using complementary metal-oxide semiconductor (CMOS) fabrication methods. However, the widespread use has been hindered because the sensing area adjoins optical and electrical components making packaging and sensor handling challenging. In this work, a local back-side release of the photonic sensor is employed, enabling a separation of the sensing area from the rest of the chip. This approach allows preserving the compatibility of photonic integrated circuits in the front-end of line and metal interconnects in the back-end of line. T2 - ATTRACT online Conference CY - Online meeting DA - 22.09.2020 KW - Silicon Photonics KW - Photonic Sensor KW - Photonic Integrated Circuits KW - Point-Of-Care-Diagnostics KW - CMOS KW - Microfluidics KW - Lab-on-a-chip KW - Ring resonator PY - 2020 UR - https://attract-eu.com/showroom/project/integration-of-biosensors-based-on-photonic-integrated-circuits-by-local-backside-etching-biopic/ SP - 1 EP - 5 AN - OPUS4-51735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Kage, D. A1 - Hoffmann, Katrin A1 - Abbandonatoa, G. A1 - Weigert, F. T1 - Biophotonics and analytics – Quantum Yields of Single Emitters and Lifetime Multiplexing N2 - An increasing number of (bio)analytical techniques rely on multiparametric analyses and the measurement of a very small number of emitters. While the former implies encoding or labeling by means of easily distinguishable properties like luminescence color or lifetime in conjunction with high-throughput optical-spectroscopic methods such as flow cytometry, the latter requires methods suitable for the characterization of the optical properties of single emitters. Here, we present the use of fluorescence correlation spectroscopy (FCS) for the relative determination of the key parameter photoluminescence quantum yield [5] and first results from flow cytometry measurements in the time-domain with a custom-designed instrument with luminescence lifetime analysis capability. T2 - ICENAP-Projekttreffens CY - Reims, Italy DA - 20.09.2018 KW - Single emitter KW - Semiconductor quantum dot KW - Lifetime KW - Multiplexing KW - Single particle spectroscopy KW - Photoluminescence quantum yield PY - 2018 AN - OPUS4-46385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Nirmalanathan-Budau, Nithiya A1 - Kraft, Marco A1 - Würth, Christian A1 - Hoffmann, Katrin A1 - Geißler, Daniel A1 - Martynenko, Irina T1 - Biophotonics and analytics - Photoluminescence properties of nanocrystals and surface group analysis N2 - Correlating the photoluminescence (PL) properties of nanomaterials like semiconductor nanocrystals (QDs) and upconversion nanocrystals (UCNPs) assessed in ensemble studies and at the single particle level and studying their surface chemistry is increasingly relevant for applications of these nanomaterials in the life and material sciences. Here we present a comparison of the spectroscopic properties of ensembles and single nanocrystalline emitters and simple methods for the quantification of functional groups and ligands on particle surfaces. The overall goal of this study was to derive particle architectures and surface chemistries well suited for spectroscopic and microscopic applications. T2 - Institutskolloqium Jozef Stefan Institute CY - Ljubljana, Slovenia DA - 07.11.20218 KW - Lanthanide KW - Nanoparticle KW - Nanocrystal KW - Upconversion KW - Absolute fluorometry KW - Integrating sphere spectroscopy KW - NIR KW - IR KW - Fluorescence KW - Surface chemistry KW - Deactivation pathways KW - Modeling KW - Photophysics KW - Size KW - Cleavable probe PY - 2018 AN - OPUS4-46578 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cruz-Alonso, M. A1 - Fernandez, B. A1 - Álvarez, L. A1 - González-Iglesias, H. A1 - Traub, Heike A1 - Jakubowski, Norbert A1 - Pereiro, R. T1 - Bioimaging of metallothioneins in ocular tissue sections by laser ablation-ICP-MS using bioconjugated gold nanoclusters as specific tags N2 - An immunohistochemical method is described to visualize the distribution of metallothioneins 1/2 (MT 1/2) and metallothionein 3 (MT 3) in human ocular tissue. It is making use of (a) antibodies conjugated to gold nanoclusters (AuNCs) acting as labels, and (b) laser ablation (LA) coupled to inductively coupled plasma – mass spectrometry (ICP-MS).Water-soluble fluorescent AuNCs (with an average size of 2.7 nm) were synthesized and then conjugated to antibody by carbodiimide coupling. The surface of the modified AuNCs was then blocked with hydroxylamine to avoid nonspecific interactions with biological tissue. Immunoassays for MT 1/2 and MT 3 in ocular tissue sections (5 μm thick) from two post mortem human donors were performed. Imaging studies were then performed by fluorescence using confocal microscopy, and LA-ICP-MS was performed in the retina to measure the signal for gold. Signal amplification by the >500 gold atoms in each nanocluster allowed the antigens (MT 1/2 and MT 3) to be imaged by LA-ICP-MS using a laser spot size as small as 4 μm. The image patterns found in retina are in good agreement with those obtained by conventional fluorescence immunohistochemistry which was used as an established reference method. KW - Metal nanoclusters KW - Fluorescence KW - Protein imaging KW - Thin tissue sections KW - Immunohistochemistry KW - Bioconjugation KW - Carbodiimide crosslinking KW - Laser ablation KW - Mass spectrometry PY - 2018 DO - https://doi.org/10.1007/s00604-017-2597-1 VL - 185 IS - 1 SP - 1 EP - 9 PB - Springer AN - OPUS4-44022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cruz-Alonso, M. A1 - Fernandez, B. A1 - Alvarez, L. A1 - Gonzalez-Iglesias, H. A1 - Traub, Heike A1 - Jakubowski, Norbert A1 - Pereiro, R. T1 - Bioimaging of metallothioneins in ocular tissue sections by laser ablation-ICP-MS using bioconjugated gold nanoclusters as specific tags N2 - An immunohistochemical method is described to visualize the distribution of metallothioneins 1/2 (MT 1/2) and metallothionein 3 (MT 3) in human ocular tissue. It is making use of (a) antibodies conjugated to gold nanoclusters (AuNCs) acting as labels, and (b) laser ablation (LA) coupled to inductively coupled plasma – mass spectrometry (ICP-MS). Water-soluble fluorescent AuNCs (with an average size of 2.7 nm) were synthesized and then conjugated to antibody by carbodiimide coupling. The surface of the modified AuNCs was then blocked with hydroxylamine to avoid nonspecific interactions with biological tissue. Immunoassays for MT 1/2 and MT 3 in ocular tissue sections (5 μm thick) from two post mortem human donors were performed. Imaging studies were then performed by fluorescence using confocal microscopy, and LA-ICP-MS was performed in the retina to measure the signal for gold. Signal amplification by the >500 gold atoms in each nanocluster allowed the antigens (MT 1/2 and MT 3) to be imaged by LA-ICP-MS using a laser spot size as small as 4 μm. The image patterns found in retina are in good agreement with those obtained by conventional fluorescence immunohistochemistry which was used as an established reference method. KW - Nanocluster KW - Immunohistochemistry KW - Laser ablation KW - ICP-MS KW - Fluorescence KW - Bioimaging PY - 2018 DO - https://doi.org/10.1007/s00604-017-2597-1 SN - 1436-5073 SN - 0026-3672 VL - 185 IS - 1 SP - 64 EP - 72 PB - Springer CY - Vienna AN - OPUS4-44637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Recknagel, Sebastian A1 - Vogel, Kristin T1 - Berechnung und Nutzung von Unsicherheiten zertifizierter Werte von Referenzmaterialien N2 - Referenzmaterialien sind unter anderem ein wichtiges Werkzeug zur Qualitätskontrolle von Messungen bestimmter Merkmalswerte. Dabei ist zu berücksichtigen, dass zertifizierte Merkmalswerte immer eine gewisse Unsicherheit haben. Die Ermittlung dieser Unsicherheitsbeiträge ist Gegenstand des Vortrags. Referenzmaterialien sind gleichzeitig ein wertvolles Werkzeug zur Ermittlung der Unsicherheit von Messverfahren und -Analysen unbekannter Proben. Die Vorgehensweise bei der Ermittlung der Messunsicherheit mit Hilfe eines Referenzmaterials wird beschrieben. T2 - Jahrestagung des GDMB-Chemiker-Ausschusses CY - Kassel, Germany DA - 07.11.2023 KW - Referenzmaterial KW - Messunsicherheit KW - ISO Guide 35 PY - 2023 AN - OPUS4-58929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Recknagel, Sebastian A1 - Vogel, Kristin T1 - Berechnung und Nutzung von Unsicherheiten zertifizierter Werte von Referenzmaterialien N2 - Referenzmaterialien sind entscheidend für die Qualitätssicherung von Laboratorien. Diese nutzen Referenzmaterialien unter anderem zur Validierung von Messverfahren und zur Kalibrierung von Geräten. Dabei ist zu beachten, dass zertifizierte Merkmalswerte stets eine gewisse Unsicherheit aufweisen. Die Ermittlung dieser Unsicherheitsbeiträge ist Gegenstand des Artikels. Des Weiteren wird ein Vorgehen beschrieben, wie die Unsicherheit von Messverfahren mit Hilfe eines Referenzmaterials bestimmt werden kann. KW - Referenzmaterial KW - Messunsicherheit KW - Qualitätskontrolle PY - 2024 DO - https://doi.org/10.1515/teme-2024-0025 SN - 0171-8096 SP - 1 EP - 7 PB - De Gruyter AN - OPUS4-60564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Klas A1 - Abele, M. A1 - Bornemann-Pfeiffer, Martin A1 - Döring, T. A1 - Falkenstein, S. A1 - Kern, S. A1 - Maiwald, Michael T1 - Benchtop NMR spectroscopy in chemical manufacturing: From hardware field integration to data modeling N2 - The use of benchtop-NMR instruments is constantly increasing during the recent years. Advantages of being affordable, portable and easy-to-operate without the need for trained staff make them especially interesting for industrial applications in quality control. However, applications of NMR spectroscopy as an online PAT tool are still very rare but offer a huge potential for process optimization and control. A key task to exploit this potential is hardware field integration of the lab-instruments in a rough environment of a chemical plant. Additionally, developments in automation and data evaluation are mandatory to ensure a robust unattended operation with low maintenance requirements. Here, we show an approach of a fully automated analyzer enclosure considering explosion safety, field communication, as well as environmental conditions in the field. Temperature sensitivity is still a limitation of benchtop-NMR instruments in flow applications. Recent developments of manufacturers allow for limited operation at static temperature levels, however, a dynamic system for continuous operation is still not available. Using a prototype system offering a larger bore, active temperature shielding studies with thermostated air were performed evaluating the performance. Automated data evaluation of NMR spectra using a modular indirect hard modeling (IHM) approach showed good results and flexibility. A second data analysis approach based on artificial neural networks (ANN) was evaluated.Therefore, amount of data was augmented to be sufficient for training. The results show comparable performance, while improving the calculation time tremendously, offering new ways to simultaneously evaluating large numbers of different models. T2 - Quantitative NMR Methods for Reaction and Process Monitoring (NMRPM) CY - Kaiserslautern, Germany DA - 24.05.2023 KW - Field integration KW - Benchtop-NMR KW - Process Analytical Technology PY - 2023 AN - OPUS4-57560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Scholtz, Lena A1 - Resch-Genger, Ute T1 - Behind the Paper - Dual color pH probes made from silica and polystyrene nanoparticles and their performance in cell studies N2 - In this contribution we highlight the importance of comparison for scientific research while developing a new, functional pH sensor system, and the valuable insights this can provide. KW - Dye KW - Optical Spectroscopy KW - pH probe KW - Silica and Polystyrene Particles KW - Nano KW - Surface groups KW - Safe-by-Design KW - Cell studies KW - Sensors KW - Particle Synthesis KW - Fluorescence PY - 2023 UR - https://communities.springernature.com/posts/dual-color-ph-probes-made-from-silica-and-polystyrene-nanoparticles-and-their-performance-in-cell-studies SP - 1 EP - 2 PB - Springer Nature CY - London AN - OPUS4-59150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dariz, P. A1 - Wortmann, U. G. A1 - Vogl, Jochen A1 - Schmid, Thomas T1 - Beautiful Pietàs in South Tyrol (Northern Italy): local or imported works of art? N2 - The study, dedicated to Beautiful Pietàs conserved in South Tyrol (Northern Italy), aims to establish, for the first time, a connection between Austroalpine raw materials and the high-fired gypsum mortars constituting the Gothic figure groups in question. The origin and chronology of this stylistically and qualitatively differing ensemble have been subject of art historical debate for nearly a century. The discourse is dominated by three main hypotheses: itinerary of an Austrian artist versus itinerary of the work of art created in an artist’s workshop in Austria versus itinerary of the stylistic vocabulary via graphical or three-dimensional models. The comparison of the δ34S values and the 87Sr/86Sr ratios of the gypsum mortars and Austroalpine sulphate deposits (in a compilation of own reference samples and literature data) points to the exploitation of sediments in the Salzkammergut and possibly also in the evaporite district of the Eastern Calcareous Alps, thus evidencing the import of the sculptures and not the activities of local South Tyrolean or itinerant artists. Two geochronological units are distinguishable: The Pietà in the Church St. Martin in Göflan can be assigned to Upper Permian raw material, whereas the metrologically consistent sculptures in the Church of Our Lady of the Benedictine Abbey Marienberg and in the Chapel St. Ann in Mölten correlate with deposits of the Early Triassic (or the Lower-Middle Triassic transition). The medieval gypsum mortars also differ in their mineralogical characteristics, i.e. in their geologically related minor components, as in the first case, characterised by a significant proportion of primary anhydrite, natural carbonate impurities mainly consist of calcite (partly converted to lime-lump-like aggregates), whereas in the second group dolomite (or rather its hydration products after pyrometamorphic decomposition) predominates, accompanied by celestine, quartz and potassium feldspar. The Pietà in the Cathedral Maria Himmelfahrt in Bozen turned out to be made of Breitenbrunn calcareous sandstone (Leitha Mountains, Burgenland, Austria), which is why the sample is not considered in the geochemical analysis. KW - High-fired gypsum mortar KW - Sulphur isotope KW - Strontium isotope KW - Polarised light microscopy KW - Raman microspectroscopy PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545610 DO - https://doi.org/10.1186/s40494-022-00678-6 SN - 2050-7445 VL - 10 IS - 1 SP - 1 EP - 17 PB - Springer Nature AN - OPUS4-54561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Klas T1 - BAM quality toolbox framework for qNMR N2 - Accreditation of analytical methods, either according to GxP or ISO regulations, requires a comprehensive quality management system. General quality documents are often already in place, which need to be extended by method-specific documentation. In this presentation we like to show an idea of a modular set of standard operating procedures (SOP) specifically developed meeting the requirements for quantitative NMR. The future goal is to collaborate with different accreditated NMR laboratories to compile a universal set of SOP and other quality documents that can be modified and used as a starting point for developing your own quality system for applications of qNMR in a regulated environment. T2 - ValidNMR Workshop at Practical Applications of NMR in Industry Conference (PANIC) CY - Online meeting DA - 22.10.2020 KW - ValidNMR KW - Validation KW - NMR spectroscopy KW - ISO 17025 KW - GxP PY - 2020 AN - OPUS4-51466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. A1 - Veiko, V. A1 - Karlagina, J. A1 - Samokhvalov, A. A1 - Polyakov, D. T1 - Back Deposition of Titanium Oxides under Laser Ablation of Titanium: Simulation and Experiment N2 - Titanium is widely used in medicine for implants and prostheses, thanks to its high biocompatibility, good mechanical properties, and high corrosion resistance. Pure titanium, however, has low wear resistance and may release metallic titanium into surrounding tissues. Structuring and coating its surface with oxide layers are necessary for high wear resistance and improved biocompatibility. In this work, a combination of theoretical and experimental methods was used to study processes responsible for deposition of titanium oxides during ablation of titanium in air. The deposition process was modeled via the Navier-Stokes equations that accounted for the material removal and accumulation of the deposit on the ablation surface. The chemical part was based on the equilibrium model embedded into the hydrodynamic code. Simulations showed that the most active zone of production of condensed titanium oxides were at plasma periphery whereas a zone of strong condensation of titanium metal was above the molten pool. In experiment, a pulsed Yb fiber laser was scanned across a titanium surface. The temperature and composition of the plasma were inferred from plasma emission spectra. The post-ablation surface was analyzed by SEM, TEM, STEM, AFM, and XRD. The developed model well reproduced the main features of experimental data. It was concluded that the deposition of condensed metal oxides from the plasma is a principal mechanism of formation of nanoporous oxide layer on the metal surface. The method of surface structuring and modification by nanosecond laser ablation can be developed into a useful technology that may find applications in medicine, photonics, and other areas. T2 - SciX 2022, The Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) CY - Cincinnati, OH, USA DA - 02.10.2022 KW - Surface coating KW - Laser ablation KW - Plasma modeling PY - 2022 AN - OPUS4-55969 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rühle, Bastian A1 - Hodoroaba, Vasile-Dan T1 - Automatic Image Segmentation and Analysis using 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 electron microscopy images “from scratch”, without the need for large training data sets of manually annotated images. 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. 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, and the segmented images can be used for automatically extracting and calculating various other particle size and shape descriptors. T2 - Machine Learning Workshop CY - Online Meeting DA - 18.03.2021 KW - Electron Microscopy KW - Neural Networks KW - Artificial Intelligence KW - Image Segmentation KW - Automated Image Analysis PY - 2021 AN - OPUS4-52304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ramos, I. I. A1 - Carl, Peter A1 - Schneider, Rudolf A1 - Segundo, M. A. T1 - Automated lab-on-valve sequential injection ELISA for determination of carbamazepine N2 - The development of an automated miniaturized analytical system that allows for the rapid monitoring of carbamazepine (CBZ) levels in serum and wastewater is proposed. Molecular recognition of CBZ was achieved through its selective interaction with microbeads carrying anti-CBZ antibodies. The proposed method combines the advantages of the micro-bead injection spectroscopy and of the flow-based platform lab-on-valve for implementation of automatic immunosorbent renewal, rendering a new recognition surface for each sample. The sequential (or simultaneous) perfusion of CBZ and the horseradish peroxidase-labelled CBZ through the microbeads is followed by real-time on-column Monitoring of substrate (3,30,5,50-tetramethylbenzidine) oxidation by colorimetry. The evaluation of the initial oxidation rate and also the absorbance value at a fixed time point provided a linear response versus the logarithm of the CBZ concentration. Under the selected assay conditions, a single analysis was completed after only 11 min, with a quantification range between 1.0 and 50 µg L⁻¹. Detection of CBZ levels in undiluted wastewater samples was feasible after a simple filtration step while good recoveries were attained for spiked certified human serum, analyzed without sample clean-up. KW - Automation KW - Bead injection spectroscopy KW - Human serum KW - Microparticles KW - Therapeutic Drug Monitoring KW - Wastewater PY - 2019 DO - https://doi.org/10.1016/j.aca.2019.05.017 SN - 0003-2670 VL - 1076 SP - 91 EP - 99 PB - Elsevier CY - Amsterdam AN - OPUS4-48317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Hoffmann, Katrin A1 - Wegmann, Marc A1 - Hannemann, M. A1 - Somma, V. A1 - Jochum, T. A1 - Niehaus, J. A1 - Roggenbuck, D. T1 - Automated determination of genotoxicity of nanoparticles with DNA-based optical assays - The NANOGENOTOX project N2 - The overall interest in nanotoxicity, triggered by the increasing use of nanomaterials in the material and life sciences, and the synthesis of an ever increasing number of new functional nanoparticles calls for standardized test procedures1,2 and for efficient approaches to screen the potential genotoxicity of these materials. Aiming at the development of fast and easy to use, automated microscopic methods for the determination of the genotoxicity of different types of nanoparticles, we assess the potential of the fluorometric γH2AX assay for this purpose. This assay, which can be run on an automated microscopic detection system, relies on the detection of DNA double strand breaks as a sign for genotoxicity3. Here, we provide first results obtained with broadly used nanomaterials like CdSe/CdS and InP/ZnS quantum dots as well as iron oxide, gold, and polymer particles of different surface chemistry with previously tested colloidal stability and different cell lines like Hep-2 and 8E11 cells, which reveal a dependence of the genotoxicity on the chemical composition as well as the surface chemistry of these nanomaterials. These studies will be also used to establish nanomaterials as positive and negative genotoxicity controls or standards for assay performance validation for users of this fluorometric genotoxicity assay. In the future, after proper validation, this microscopic platform technology will be expanded to other typical toxicity assays. T2 - SPIE 2018 CY - San Francisco, USA DA - 27.01.2018 KW - Nanoparticle KW - Fluorescence KW - Surface chemistry KW - Size KW - Assay KW - Microscopy KW - Nanotoxicity KW - Toxicity KW - Automation KW - Calibration KW - Standard PY - 2018 AN - OPUS4-44186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Morcillo, Dalia A1 - Abad Andrade, Carlos Enrique A1 - Winckelmann, Alexander A1 - Frick, D. A1 - Jacobsen, L. A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Vogl, Jochen A1 - Panne, Ulrich T1 - Atomic absorption spectroscopy and machine learning for lithium isotopic study N2 - The isotopic analysis of lithium is also relevant to the study of geological phenomena.1 In this work we propose improvements to the method for the isotopic analysis of lithium using a high-resolution continuum source atomic absorption spectrometer (HR-CS-AAS) coupled to a double echelle modular spectrometer (DEMON). 2 This tool for isotopic ratio determination is based on monitoring the isotopic components of lithium by their spin-orbit coupling and its isotopic shift of about 15 pm for the 22P←2 2S electronic transition around 670.788 nm. The data analysis was carried out by using a decision-tree-based ensemble machine learning (ML) algorithm. For the training of the algorithm (XGBoost), a set of samples with 6Li isotope amount fractions ranging from 0.06 to 0.99 mol-1 was used. Subsequently, the procedure was validated of a set of stock chemicals (Li2CO3, LiNO3, LiCl and LiOH) and a BAM candidate reference material, the cathode material LiNi1/3Mn1/3Co1/3O2 (NMC111). Finally, the ML model was applied to the set of geological samples, previously digested, for the determination of their isotope ratio. The optical resolution was improved from 140,000 to 790,000 to better deconvolution the lithium isotopic components in the atomic spectrum. And the method was compared with multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The results are metrologically comparable. T2 - Colloquium Spectroscopicum Internationale XLII (CSI XLII) CY - Gijón, Spain DA - 30.05.2022 KW - Lithium isotope KW - Atomic absorption spectroscopy PY - 2022 AN - OPUS4-56357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Morcillo, Dalia A1 - Winckelmann, Alexander A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Riedel, Jens A1 - Vogl, Jochen A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Atomic absorption spectrometry with machine learning as a tool for lithium isotope analysis N2 - The general interest in the implementation of renewable energies, particularly in the development of lithium-ion batteries, makes lithium a key element to be analyzed. We are working to develop this tool to determine if the isotopic effect of lithium has an impact on battery aging. T2 - SALSA Konferenz CY - Berlin, Germany DA - 16.09.2021 KW - Atomic absorption spectrometry KW - Battery KW - Machine learning KW - Lithium KW - Isotope PY - 2021 AN - OPUS4-53693 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Biesen, L. A1 - Krenzer, J. A1 - Nirmalananthan-Budau, Nithiya A1 - Resch-Genger, Ute A1 - Müller, Th. J. J. T1 - Asymmetrically bridged aroyl-S,N-ketene acetalbased multichromophores with aggregationinduced tunable emission N2 - Asymmetrically bridged aroyl-S,N-ketene acetals and aroyl-S,N-ketene acetal multichromophores can be readily synthesized in consecutive three-, four-, or five-component syntheses in good to excellent yields by several successive Suzuki-couplings of aroyl-S,N-ketene acetals and bis(boronic)acid esters. Different aroyl-S,N-ketene acetals as well as linker molecules yield a library of 23 multichromophores with substitution and linker pattern-tunable emission properties. This allows control of different communication pathways between the chromophores and of aggregation-induced emission (AIE) and energy transfer (ET) properties, providing elaborate aggregation-based fluorescence switches. KW - Dye KW - Aggregation KW - Aggregation induced emission KW - Signal enhancement KW - Energy transfer KW - Switch KW - Sensor KW - Quantum yield KW - Lifetime KW - Photophysics KW - Sythesis KW - Nanaoparticle PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550719 DO - https://doi.org/10.1039/d2sc00415a VL - 13 SP - 5374 EP - 5381 PB - Royal Society of Chemistry AN - OPUS4-55071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keller, S. A1 - Borde, T. A1 - Brangsch, J. A1 - Reimann, C. A1 - Kader, A. A1 - Schulze, D. A1 - Buchholz, R. A1 - Kaufmann, Jan Ole A1 - Karst, U. A1 - Schellenberger, E. A1 - Hamm, B. A1 - Makowski, M. R. T1 - Assessment of the hepatic tumor extracellular matrix using elastin‑specific molecular magnetic resonance imaging in an experimental rabbit cancer model N2 - To investigate the imaging performance of an elastin-specific molecular magnetic resonance imaging (MRI) probe with respect to the extracellular matrix (ECM) in an experimental hepatic cancer model. Twelve rabbits with hepatic VX2 tumors were examined using 3 T MRI 14, 21, and 28 days after tumor implantation for two subsequent days (gadobutrol, day 1; elastin-specific probe, day 2). The relative enhancement (RE) of segmented tumor regions (central and margin) and the peritumoral matrix was calculated using pre-contrast and delayed-phase T1w sequences. MRI measurements were correlated to histopathology and element-specific and spatially resolved mass spectrometry (MS). Mixed-model analysis was performed to assess the performance of the elastin-specific probe. In comparison to gadobutrol, the elastin probe showed significantly stronger RE, which was pronounced in the tumor margin (day 14–28: P ≤ 0.007). In addition, the elastin probe was superior in discriminating between tumor regions (χ2(4) = 65.87; P < 0.001). MRI-based measurements of the elastin probe significantly correlated with the ex vivo elastinstain (R = .84; P <0 .001) and absolute gadolinium concentrations (ICP-MS: R = .73, P <0 .01). LA-ICP-MS imaging confirmed the colocalization of the elastin-specific probe with elastic fibers. Elastin-specific molecular MRI is superior to non-specific gadolinium-based contrast agents in imaging the ECM of hepatic tumors and the peritumoral tissue. KW - Elastin-specific molecular agent KW - Extracellular matrix KW - Hepatocellular carcinoma KW - Inductively coupled plasma mass spectroscopy KW - Laser ablation-inductively coupled plasma-mass spectrometry KW - Magnetic resonance imaging KW - MR imaging KW - ESMA KW - Gadolinium PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517360 DO - https://doi.org/10.1038/s41598-020-77624-8 VL - 10 IS - 1 SP - 20785 PB - Nature AN - OPUS4-51736 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -