TY - CONF A1 - Pérez-Padilla, Victor T1 - Direct detection of glyphosate in water with fluorescent molecularly imprinted polymer particles N2 - Analysis of environmental contaminants such as pesticides is increasing in importance due to frequent detection of residues in water reserves and food stuff, as well as lowering of maximum residue levels (MRLs). Molecularly imprinted polymers (MIPs) have been developed for preconcentration of these analytes prior to analysis by chromatographic techniques [1]. MIPs are prepared by polymerization of monomers in a matrix containing the analyte, followed by extraction of the analyte to obtain binding sites that are complementary to the analyte of interest. Recently, our group developed MIPs containing fluorescent reporter molecules that can be used for direct detection and quantification of 2,4-D in contaminated water. Core/shell MIP particles were employed, consisting of sub-micron silica nanoparticles coated with a MIP shell containing a fluorescent reporter whose signal was enhanced upon binding with 2,4-D in water. A limit of detection of 20 nM was attained [2]. We present here a comparable system, composed of fluorescent core-shell MIPs for the direct analysis of pesticides in environmental samples. T2 - UK-Poland-Ukraine Bioinspired Materials Conference CY - Online meeting DA - 29.11.2022 KW - Core-Shell Particles KW - Fluorescent Probes KW - Molecularly Imprinted Polymers KW - Glyphosate KW - Guanidinium Receptors PY - 2022 AN - OPUS4-56514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döring, Sarah T1 - Nontarget mass spectrometry and recombinant antibody panels for optimized protein metrology N2 - The metrological analysis uses an unbroken chain of comparative measurements to trace results back to the national or international standard. This enables comparable, absolute quantification between laboratories. In 2020/2021, a pilot study for the quantification of SARS-CoV-2 antibodies was initiated with the involvement of BAM. Despite the consistent use of ID-MS, a large discrepancy in the results of the participating laboratories was found. This was the motivation for a project to systematically investigate and optimize traceable methods of protein quantification using mass spectrometric nontarget analysis (NTA) and recombinant antibody panels. T2 - St Nicholas Mass Spectrometry Symposium CY - Berlin, Germany DA - 08.12.2022 KW - Antibody quantification KW - Metrology KW - Traceability PY - 2022 AN - OPUS4-56515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lisec, Jan T1 - ABID N2 - In order to automate the spectral comparison for larger libraries of antibodies, we developed the online software ABID 2.0. This open-source software determines the number of matching peptides in the fingerprint spectra. We propose that publications and other documents critically relying on monoclonal antibodies with unknown amino acid sequences should include at least one antibody fingerprint. By fingerprinting an antibody in question, its identity can be confirmed by comparison with a library spectrum at any time and context. KW - Software KW - Antibody KW - MALDI PY - 2022 UR - https://github.com/BAMresearch/ABID PB - GitHub CY - San Francisco, CA, USA AN - OPUS4-56192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Bernd R. T1 - Untersuchung der Integrität von glasfaserverstärkten Zahnstiften mittels Synchrotron-Röntgenrefraktion N2 - Die Integrität der Verstärkungsfasern in Komposit-Zahnstiften ist entscheidend für die Biegefestigkeit und die langfristige Haftung am Zement in den Wurzelkanälen. Es wurde vermutet, dass die Integrität von glasfaserverstärkten Zahnstiften durch das Beschleifen während der zahnmedizinischen Behandlung beeinträchtigt wird. Eine Beschädigung der Fasern führt zu einer erheblichen strukturellen Schwächung über den gesamten Stiftdurchmesser. Glasfragmente, die durch den Kontakt mit dem Zahnbohrer entstehen, können sich vom Stift lösen und die Haftfähigkeit erheblich verringern. Mit Hilfe hochauflösender Synchrotron-Röntgen-Refraktions-Radiographie (SXRR) konnte das Ausmaß der Schäden zuverlässig identifiziert und charakterisiert werden. Dazu wurden die Glasfaserstifte sowohl im Herstellungszustand als auch nach der Bearbeitung mit einem Diamantbohrer untersucht. Die Datensätze wurden zur Visualisierung und Quantifizierung der morphologischen Charakteristika intakter und durch das Beschleifen beschädigter Regionen analysiert. Sie zeigen Schäden im bearbeiteten Bereich (z. B. Brüche, Splitter und Risse) sowie herstellungsbedingte Inhomogenitäten der Fasern mit einer signifikanten Zunahme der inneren Oberflächen in Probenregionen, die durch das Beschleifen beschädigt wurden. T2 - DGZfP Jahrestagung 2022 CY - Kassel, Germany DA - 23.05.2022 KW - Röntgen-Refraktion KW - Verbundwerkstoffe KW - Zahnstifte PY - 2022 AN - OPUS4-54924 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Olbrich, Adelina-Elisa T1 - Multielemental analysis of MIC organisms grown on solid steel samples by means of single cell-ICP-ToF-MS N2 - Inductively coupled plasma-time of flight-mass spectrometry (ICP-ToF-MS) enables the analysis of the multi-element fingerprint of individual cells due to a (quasi-)simultaneous detection of about 70 elements of the periodic table. The interface between material and environmental analysis thus receives special attention, e.g., when considering corrosion processes. Microbiologically influenced corrosion (MIC) is a highly unpredictable phenomenon due to the influence of the environment, microbial communities involved and the respective electron source. However, the interaction pathway between cells and the metal surface remains unclear. The development of the MIC-specific ICP-ToF-MS analytical method presented here, in combination with the investigation of steel-MIC interactions, contributes significantly to progress in instrumental MIC analysis and will enable clarification of the processes taking place. For this, a MIC-specific staining procedure was developed which ensures the analysis of intact cells. It allows the studies of archaea at a single cell level which is extremely scarce compared to other well characterized organisms. Additionally, the single cell ICP-ToF-MS is used for the analysis of archaea involved in MIC of steel. Hence, the possible uptake of individual elements from different steel samples is investigated - the information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research. T2 - DGMS Young Scientists Fall Meeting 2022 CY - Hünfeld, Germany DA - 28.09.2022 KW - Single cell KW - Microbiological influenced corrosion MIC KW - Sc-ICP-ToF-MS KW - Method development PY - 2022 AN - OPUS4-55910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Bernd R. A1 - Soares, A.P. A1 - Kupsch, Andreas A1 - Baum, D. A1 - Hesse, B. A1 - Zaslansky, P. T1 - Untersuchung der Integrität von glasfaserverstärkten Zahnstiften mittels Synchrotron-Röntgenrefraktion N2 - Die Integrität der Verstärkungsfasern in Komposit-Zahnstiften ist entscheidend für die Biegefestigkeit und die langfristige Haftung am Zement in den Wurzelkanälen. Es wurde vermutet, dass die Integrität von glasfaserverstärkten Zahnstiften durch das Beschleifen während der zahnmedizinischen Behandlung beeinträchtigt wird. Eine Beschädigung der Fasern führt zu einer erheblichen strukturellen Schwächung über den gesamten Stiftdurchmesser. Glasfragmente, die durch den Kontakt mit dem Zahnbohrer entstehen, können sich vom Stift lösen und die Haftfähigkeit erheblich verringern. Mit Hilfe hochauflösender Synchrotron-Röntgen-Refraktions-Radiographie (SXRR) konnte das Ausmaß der Schäden zuverlässig identifiziert und charakterisiert werden. Dazu wurden die Glasfaserstifte sowohl im Herstellungszustand als auch nach der Bearbeitung mit einem Diamantbohrer untersucht. Die Datensätze wurden zur Visualisierung und Quantifizierung der morphologischen Charakteristika intakter und durch das Beschleifen beschädigter Regionen analysiert. Sie zeigen Schäden im bearbeiteten Bereich (z. B. Brüche, Splitter und Risse) sowie herstellungsbedingte Inhomogenitäten der Fasern mit einer signifikanten Zunahme der inneren Oberflächen in Probenregionen, die durch das Beschleifen beschädigt wurden. T2 - DGZfP Jahrestagung 2022 CY - Kassel, Germany DA - 23.05.2022 KW - Röntgen-Refraktion KW - Verbundwerkstoffe KW - Zahnstifte PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549231 SP - 1 EP - 7 AN - OPUS4-54923 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Y. T1 - Fluid inclusion microthermometry in stalagmites: The next stage of development N2 - Fluid inclusion microthermometry is one of the analytical approaches that has been proposed for speleothem-based temperature reconstructions. The proxy of this paleothermometer is the density of drip water relicts that have been enclosed in microscopic fluid inclusions during speleothem growth. Prior to microthermometric analyses, the monophase liquid inclusions need to be transferred from a metastable liquid into a stable liquid-vapour two-phase state by stimulating vapour bubble nucleation by means of single ultra-short laser pulses. Subsequent microthermometric analyses determine the temperature at which the vapour bubble disappears again, the so-called liquid-vapour homogenisation temperature (Th(obs) ). The observed homogenisation temperature depends not only on the water density but also on the inclusion volume. In order to determine the water density, a thermodynamic model is used that takes account of the effect of surface tension on Th(obs) to calculate Th∞. This is the corresponding homogenisation temperature at saturation pressure that determines the water density and defines the formation temperature of the fluid inclusion. The analytical precision of the method ranges between 0.1 and 0.3 °C depending on the size of the inclusions. T2 - Climate Change: The Karst Record IX (KR9) CY - Innsbruck, Austria DA - 17.07.2022 KW - Fluid inclusion microthermometry KW - Stalagmites KW - Synchrotron radiation KW - X-ray imaging KW - X-ray diffraction PY - 2022 AN - OPUS4-55344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Olbrich, Adelina-Elisa T1 - Deciphering microbiological influenced corrosion processes on steel with single cell-ICP-ToF-MS N2 - Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. The information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research. References. T2 - Future WiNS CY - Berlin, Germany DA - 07.12.2022 KW - Single cell KW - Microbiological influenced corrosion MIC KW - Sc-ICP-ToF-MS KW - Method development KW - Ir DNA staining approach KW - Carbon steel corrosion PY - 2022 AN - OPUS4-56567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Srivastava, Priyanka A1 - Tavernaro, Isabella A1 - Genger, C. A1 - Welker, P. A1 - Huebner, Oskar A1 - Resch-Genger, Ute T1 - Multicolor Polystyrene Nanosensors for the Monitoring of Acidic, Neutral, and Basic pH Values and Cellular Uptake Studies N2 - A first tricolor fluorescent pH nanosensor is presented, which was rationally designed from biocompatible carboxylated polystyrene nanoparticles and two analyte-responsive molecular fluorophores. Its fabrication involved particle staining with a blue-red-emissive dyad, consisting of a rhodamine moiety responsive to acidic pH values and a pH-inert quinoline fluorophore, followed by the covalent attachment of a fluorescein dye to the particle surface that signals neutral and basic pH values with a green fluorescence. These sensor particles change their fluorescence from blue to red and green, depending on the pH and excitation wavelength, and enable ratiometric pH measurements in the pH range of 3.0−9.0. The localization of the different sensor dyes in the particle core and at the particle surface was confirmed with fluorescence microscopy utilizing analogously prepared polystyrene microparticles. To show the application potential of these polystyrene-based multicolor sensor particles, fluorescence microscopy studies with a human A549 cell line were performed, which revealed the cellular uptake of the pH nanosensor and the differently colored emissions in different cell organelles, that is, compartments of the endosomal-lysosomal pathway. Our results demonstrate the underexplored potential of biocompatible polystyrene particles for multicolor and multianalyte sensing and bioimaging utilizing hydrophobic and/or hydrophilic stimuli-responsive luminophores. KW - Microparticle KW - Fluorescence KW - Sensor KW - pH KW - Quantum yield KW - Multiplexing KW - Imaging KW - Cell KW - Quality assurance KW - Nano KW - Polymer KW - Bioimaging KW - Particle KW - Application PY - 2022 DO - https://doi.org/10.1021/acs.analchem.2c00944 VL - 94 IS - 27 SP - 9656 EP - 9664 PB - ACS AN - OPUS4-55365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, Cui A1 - Reichenauer, F. A1 - Kitzmann, W.R. A1 - Kerzig, Ch. A1 - Heintze, K. A1 - Resch-Genger, Ute T1 - Efficient Triplet-Triplet Annihilation Upconversion Sensitized by a Chromium(III) Complex via an Underexplored Energy Transfer Mechanism N2 - Sensitized triplet-triplet annihilation upconversion (sTTA-UC) mainly relies on precious metal complexes thanks to their high intersystem crossing (ISC) efficiencies, excited state energies, and lifetimes, while complexes of abundant first-row transition metals were only rarely utilized and with often moderate UC quantum yields. [Cr(bpmp)2]3+ (bpmp = 2,6-bis(2-pyridylmethyl)pyridine) containing earth-abundant chromium possesses an absorption band suitable for green light excitation, a doublet excited state energy matching the triplet energy of 9,10-diphenyl anthracene (DPA), a close to millisecond excited state lifetime, and high photostability. Combined ISC and doublet-triplet energy transfer from excited [Cr(bpmp)2]3+ to DPA gives 3DPA with close-to-unity quantum yield. TTA of 3DPA furnishes greento-blue UC with a quantum yield of 12.0 % (close to the theoretical maximum). Sterically less-hindered anthracenes undergo a [4+4] cycloaddition with [Cr(bpmp)2]3+ and green light. KW - Fluorescence KW - Optical probe KW - Sensor KW - ph KW - Quantum yield KW - Quality assurance KW - Cr(III) KW - Lifetime KW - Ligand KW - Theory KW - TTA-UC KW - Energy transfer KW - Upconversion KW - Mechanism KW - Anthracene KW - Photochemistry KW - DFT KW - Cycloaddition KW - Transient absorbtion spectroscopy PY - 2022 DO - https://doi.org/10.1002/anie.202202238 VL - 61 IS - 24 SP - 1 EP - 8 PB - Wiley online library AN - OPUS4-54604 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Güttler, Arne A1 - Richter, Maria A1 - Würth, Christian A1 - Resch-Genger, Ute T1 - New Reference Materials for Quantification and Standardization of Fluorescence-based Measurements N2 - Luminescence techniques are amongst the most commonly used analytical methods in the life and material sciences due to their high sensitivity and non-destructive and multiparametric character. Photoluminescence signals are, however, affected by wavelength-, polarization-, and time-dependent instrument specific effects and the compound-specific photoluminescence quantum yield. The former hamper the comparability of fluorescence measurements, while the relative determination of the latter requires suitable quantum yield standards with well-known photoluminescence quantum yields. For the simple correction of instrument specific effects in the wavelength region of 300 nm to 950 nm, the set of the five certified spectral fluorescence standards (CRM) BAM-F001 – BAM-F005, has been extended to the NIR range by including two new fluorescence standards currently under certification. T2 - 17th conference on Methods and Applications in Fluorescence CY - Gothenburg, Sweden DA - 11.09.2022 KW - Luminescence KW - Photoluminescence KW - Fluorescence KW - Quantum yield KW - Certified reference material KW - Standard PY - 2022 AN - OPUS4-56441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholtz, Lena T1 - Luminescence encoding of polymer microbeads with nanocrystals during polymerization N2 - The Goal & Motivation - Spherical polymer beads - Controlled size in the low µm range - Narrow size distribution - Homogeneous encoding with molecular and nanoscale luminophores (dyes , QDs, platelets etc.) - Sufficient fluorescence - Easy, accessible procedure T2 - GrK Nanohybrid Conference CY - Hamburg, Germany DA - 04.10.2022 KW - Polymerization KW - Nanocrystals KW - Fluorescence KW - Microbeads PY - 2022 AN - OPUS4-56028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Billimoria, K. A1 - Diaz Fernandez, Y. A. A1 - Andresen, Elina A1 - Sorzabal-Bellido, I. A1 - Huelga-Suarez, G. A1 - Bartczak, D. A1 - Ortiz de Solórzano, C. A1 - Resch-Genger, Ute A1 - Goenaga Infante, H. T1 - The potential of bioprinting for preparation of nanoparticle-based calibration standards for LA-ICP-ToF-MS quantitative imaging N2 - This paper discusses the feasibility of a novel strategy based on the combination of bioprinting nano-doping technology and laser ablation-inductively coupled plasma time-of-flight mass spectrometry analysis for the preparation and characterization of gelatin- based multi-element calibration standards suitable for quantitative imaging. To achieve this, lanthanide up-conversion nanoparticles were added to a gelatin matrix to produce the bioprinted calibration standards. The features of this bioprinting approach were com- pared with manual cryosectioning standard preparation, in terms of throughput, between batch repeatability and elemental signal homogeneity at 5 μm spatial resolution. By using bioprinting, the between batch variability for three independent standards of the same concentration of 89 Y (range 0–600 mg/kg) was reduced to 5% compared to up to 27% for cryosectioning. On this basis, the relative standard deviation ( RSD ) obtained between three independent calibration slopes measured within 1 day also reduced from 16% (using cryosectioning ) to 5% (using bioprinting), supporting the use of a single standard preparation replicate for each of the concentrations to achieve good calibration performance using bioprinting. This helped reduce the analysis time by approximately 3-fold. With cryosectioning each standard was prepared and sectioned individually, whereas using bio-printing it was possible to have up to six different standards printed simultaneously, reducing the preparation time from approximately 2 h to under 20 min (by approxi- mately 6-fold). The bio-printed calibration standards were found stable for a period of 2 months when stored at ambient temperature and in the dark. KW - Environmental analysis KW - LA-ICP-MS KW - Lanthanide KW - Tag KW - Fluorescence KW - Nanoparticles KW - Reference material KW - Quality assurance KW - 3D-printing KW - Synthesis KW - Production KW - Multimodal PY - 2022 DO - https://doi.org/10.1093/mtomcs/mfac088 SN - 1756-591X VL - 14 IS - 12 SP - 1 EP - 9 PB - Oxford University Press CY - Oxford AN - OPUS4-57018 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wegner, Karl David T1 - Luminescent Quantum dots – the next-generation nano light bulbs N2 - Fluorescent semiconductor nanocrystals, also known as quantum dots (QDs), enabled many advancements in biotechnology, photovoltaics, photocatalysis, quantum computing and display devices. The high versatility of this nanomaterial is based on their unique size-tunable photoluminescence properties, which can be adjusted from the visible to the near-infrared range. In contrast to other nanomaterials, QDs made the transition from a laboratory curiosity to the utilization in commercial products, like the QLED television screen or in smartphone displays. The best investigated QDs are composed of heavy metals like cadmium or lead, which is not the best choice in terms of toxicity and environmental pollution. A more promising material is Indium Phosphide (InP), which is also currently used by Samsung, Sony and co. in the QLED displays. In this contribution, I would like to give you a sneak peek behind the curtains of nanomaterial synthesis and show how this material is produced, how to stabilize their structural properties, and assess their toxicity in environmentally relevant conditions. Furthermore, I would like to present a synthesis method to accomplish the last open challenge in display technology of a blue luminescent LED based on QDs by introducing a new element to the InP QDs. T2 - The Berlin Postdoc Day CY - Berlin, Germany DA - 03.11.2022 KW - InP KW - Quantum dots KW - Fluorescence KW - Aging KW - Doping KW - Nanomaterial KW - Cytotoxicity PY - 2022 AN - OPUS4-56194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Functional molecular chromophores and nanomaterials reporters, optical probes, and sensors N2 - •Overview of expertise of division Biophotonics •Functional molecular and nanoscale luminescent reporters, probes, and sensors including design principles available from division Biophotonics •Examples for pH and O2 responsive molecular probes and particle sensors •Surface group quantification Analytical methods and cleavable probes •Concepts & standards for the validation and traceability of optical measurements T2 - FU-Seminar CY - Berlin, Germany DA - 09.12.2022 KW - Particle sensors KW - Surface group quantification KW - Nanoscale luminescent reporters KW - Cleavable probes PY - 2022 AN - OPUS4-56526 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Goryacheva, O. A. A1 - Wegner, Karl David A1 - Sobolev, A. M. A1 - Häusler, I. A1 - Gaponik, N. A1 - Gorycheva, I. Y. A1 - Resch-Genger, Ute T1 - Influence of particle architecture on the photoluminescence properties of silica‑coated CdSe core/shell quantum dots N2 - Light-emitting nanoparticles like semiconductor nanocrystals (termed quantum dots, QDs) are promising candidates for biosensing and bioimaging applications based on their bright and stable photoluminescent properties. As high-quality QDs are often synthesized in organic solvents, strategies needed to be developed to render them water-dispersible without affecting their optical properties and prevent changes in postmodification steps like the biofunctionalization with antibodies or DNA. Despite a large number of studies on suitable surface modification procedures, the preparation of water-soluble QDs for nanobiotechnology applications still presents a challenge. To highlight the advantages of surface silanization, we systematically explored the influence of the core/multishell architecture of CdSe/CdS/ZnS QDs and the silanization conditions on the optical properties of the resulting silanized QDs. Our results show that the optical properties of silica-coated CdSe/CdS/ZnS QDs are best preserved in the presence of a thick CdS (6 monolayers (ML)) intermediate shell, providing a high photoluminescence quantum yield (PL QY), and a relatively thick ZnS (4.5 ML) external shell, effectively shielding the QDs from the chemical changes during silica coating. In addition to the QD core/shell architecture, other critical parameters of the silica-coating process, that can have an influence on the optical properties of the QD, include the choice of the surfactant and its concentration used for silica coating. The highest PL QY of about 46% was obtained by a microemulsion silica-coating procedure with the surfactant Brij L4, making these water-dispersible QDs to wellsuited optical reporters in future applications like fluorescence immunoassays, biomedicine, and bioimaging. KW - Nano KW - Nanomaterial KW - Particle KW - Semiconductor KW - Quantum do KW - Photoluminescence KW - Photophysics KW - Lifetime KW - Sensor KW - Mechanism KW - Surface KW - Shell KW - Silica KW - Silanization KW - Synthesis PY - 2022 DO - https://doi.org/10.1007/s00216-022-04005-7 SP - 1 EP - 13 PB - Springer AN - OPUS4-54546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella T1 - Development of amorphous silica particle based reference materials for surface functional group quantification N2 - Functionalized nanomaterials (NM) with their unique size-dependent properties are of increasing relevance for current and future developments in various fields such as medical and pharmaceutical industry, computing, electronics or food and consumer products. The performance and safety of NM are determined by the sum of their intrinsic physicochemical properties.1 Besides other key parameters, the particle surface chemistry, which is largely controlled by the chemical nature and density of functional groups and ligands, must be considered for a better performance, stability, and processibility of NM, as well as their interaction with the environment. Thus, particle standards with well-designed surfaces and methods for functional group quantification can foster the sustainable development of functional and safe(r) NM.2 Here we provide a brief overview of the ongoing research in division Biophotonics to design tailored amorphous silica reference particles with bioanalytically relevant functional groups and ligands, for the development of standardized and validated surface functional group quantification methods. T2 - Workshop NanoRiskSD project CY - Berlin, Germany DA - 09.06.2022 KW - Nanoparticle KW - Surface analysis KW - Silica KW - Fluorescence KW - Assay PY - 2022 AN - OPUS4-55004 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Monks, M.-J. A1 - Würth, Christian A1 - Kemnitz, Erhard A1 - Resch-Genger, Ute T1 - Dopant ion concentration-dependent upconversion luminescence of cubic SrF2:Yb3+, Er3+ nanocrystals prepared by a fluorolytic sol–gel method N2 - A fluorolytic sol–gel method was used for the fast and simple synthesis of small cubic-phase SrF2:Yb3+, Er3+ upconversion (UC) nanocrystals (UCNC) of different composition at room temperature. Systematic studies of the crystal phase and particle size of this Yb3+,Er3+-concentration series as well as excitation power density (P)-dependent UC luminescence (UCL) spectra, UCL quantum yields (ΦUCL), and UCL decay kinetics yielded maximum UCL performance for doping amounts of Yb3+ of 13.5% and Er3+ of 1.3% in the studied doping and P-range (30–400 W cm−2). Furthermore, ΦUCL were determined to be similar to popular β-NaYF4:Yb3+,Er3+. The relative spectral UCL distributions revealed that all UCNC show a strong red emission in the studied doping and P-range (30–400 W cm−2) and suggest that the UCL quenching pathway for unshelled cubic-phase SrF2:Yb3+,Er3+ UCNC differs from the commonly accepted population and depopulation pathways of β-NaYF4:Yb3+,Er3+ UCNC. In SrF2:Yb3+,Er3+ UCNC the 4S3/2 → 4I13/2 transition exhibits a notably stronger sensitivity towards P and reveals increasing values for decreasing Yb3+–Yb3+ distances while the 4I9/2 → 4I15/2 transition is significantly less affected by P and energy migration facilitated UCL quenching. These results emphasize the complexity of the UC processes and the decisive role of the crystal phase and symmetry of the host lattice on the operative UCL quenching mechanism in addition to surface effects. Moreover, the room temperature UCNC synthesis enabled a systematic investigation of the influence of the calcination temperature on the crystal phase of powder-UCNC and the associated UCL properties. Calcination studies of solid UCNC of optimized doping concentration in the temperature range of 175 °C and 800 °C showed the beneficial influence of temperature- induced healing of crystal defects on UCL and the onset of a phase separation connected with the oxygenation of the lanthanide ions at elevated temperature. This further emphasizes the sensitivity of the UC process to the crystal phase and quality of the host matrix. KW - Upconversion nanoparticle KW - Lanthanide KW - Photophysics KW - Synthesis PY - 2022 DO - https://doi.org/10.1039/d2nr02337g SP - 1 EP - 10 PB - Royal Society of Chemistry AN - OPUS4-55364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholtz, Lena T1 - Luminescent Polymer Microbeads – Synthesis & Applications N2 - Differently sized, luminescent polymer beads encoded with QDs were prepared with a simple, optimized polymerization procedure. The optical properties of the resulting particles were studied to ensure sufficient fluorescence. In addition, possible future applications were identified. T2 - Future WiNS: New Energies for a Sustainable World CY - Berlin, Germany DA - 07.12.2022 KW - Polymerization KW - Quantum dots KW - Fluorescence KW - Luminescence PY - 2022 AN - OPUS4-56560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella T1 - Quantification of the Total and Accessible Number of Functional Groups and Ligands on Nanomaterials N2 - Surface-functionalized organic and inorganic nanoparticles (NP) are of great interest in the life and material sciences, as they can be used e.g. as drug carriers, fluorescent sensors, and multimodal labels in bioanalytical assays and imaging applications. NP performance in such applications depends not only on particle size, size distribution, and morphology, but also on surface chemistry, i.e. the total number of surface functional groups (FG) and the number of FG accessible for subsequent functionalization with ligands or biomolecules, which in turn determines surface charge, colloidal stability, biocompatibility, and toxicity. Methods for FG quantification should be simple, robust, reliable, fast, and inexpensive, and allow for the characteriza-tion of a broad variety of nanomaterials differing in size, chemical composition, and optical properties. Aiming at the development of simple, versatile, and multimodal tools for the quantification of many bioanalytically relevant FG such as amine, carboxy, thiol and aldehyde functionalities, we investigated and compared various analytical methods commonly used for functional group quantification. This includes electrochemical titration methods, dye-based optical assays, and other instrumental analytical techniques such as nuclear magnetic resonance, mass spectrometry, and thermal analysis methods. T2 - Nanotech France CY - Paris, France DA - 15.06.2022 KW - Optical assays KW - Functionalized nano- and microparticles KW - Particle surface analysis KW - Surface group quantification KW - Terminal functional groups PY - 2022 AN - OPUS4-55208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuner, Maximilian T1 - Cleaving ergot alkaloids - development of a novel food screening method N2 - Mycotoxins (toxic compounds formed by fungi) in food and feed have caused problems for mankind since the beginning of time. The group of ergot alkaloids plays a special role in human history. Several tens of thousands of deaths during the middle ages caused by to ergotism (the disease caused by continuous intake of ergot alkaloid contaminated food) underscore the importance of reliable analytical methods to ensure food safety. More than 50 compounds belong to the group of ergot alkaloids. The 12 most found structures – the major ergot alkaloids – are typically measured, when it comes to ergot alkaloid quantification. High performance liquid chromatography (HPLC) with a fluorescence detector (FLD) is typically used to quantify the ergot alkaloid content. The main disadvantage of this method are the high costs for calibration standards (12 different calibration substances are required). But also, the time and effort required for the analysis of 12 peaks and overlapping signals that occur in complex food samples such as bread. As all ergot alkaloids share the ergoline structure and just differ in the substituents attached to this backbone, measurement of all ergot alkaloids in one sum parameter presents a time and cost saving alternative. The most important step for the development of such a sum parameter method is the reaction used to transfer all ergot alkaloids to one uniform structure. Two promising reactions, the acidic esterification to lysergic acid methyl ester and hydrazinolysis to lysergic acid hydrazide, were examined for possible use in a routine analysis method. In addition to yield and reaction rate, factors such as handling of the reaction and the possibility of parallel sample workup play a role. T2 - Adlershofer Forschungsforum 2022 CY - Berlin, Germany DA - 11.11.2022 KW - Ergot alkaloids KW - Screening PY - 2022 AN - OPUS4-56585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Boehm, U. A1 - Nelson, G. A1 - Brown, C. M. A1 - Bagley, S. A1 - Bajcsy, P. A1 - Bischof, J. 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. M. A1 - Resch-Genger, Ute A1 - Schuetz, L. C. A1 - Seitz, A. A1 - Strambio-De-Castillia, C. A1 - Swedlow, J. R. A1 - Nitschke, R. T1 - Author correction: QUAREP-LiMi: a community endeavor to advance quality assessment and reproducibility in light microscopy N2 - This is a corrigendum to the original article "QUAREP-LiMi: a community endeavor to advance quality assessment and reproducibility in light microscopy" that was published in the journal "Nature methods", vol. 18 (2021), pp. 1424-1427. PY - 2022 DO - https://doi.org/10.1038/s41592-021-01387-x SN - 1548-7105 SP - 1 PB - Nature Publishing Group CY - London AN - OPUS4-54270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fa, X. A1 - Lin, Sh. A1 - Yang, J. A1 - Shen, Ch. A1 - Liu, Y. A1 - Gong, Y. A1 - Qin, A. A1 - Ou, Jun A1 - Resch-Genger, Ute T1 - −808 nm-activated Ca2+ doped up-conversion nanoparticles that release no inducing liver cancer cell (HepG2) apoptosis N2 - Anear-infrared (NIR) light-triggered release method for nitric oxide (NO) was developed utilizing core/shell NaYF4: Tm/Yb/Ca@NaGdF4:Nd/Yb up-conversion nanoparticles (UCNPs) bearing a mesoporous silica (mSiO2) shell loaded with theNOdonor S-nitroso-N-acetyl-DL-penicillamine (SNAP). To avoid overheating in biological samples, Nd3+ was chosen as a sensitizer, Yb3+ ions as the bridging sensitizer, andTm3+ ions as UV-emissive activator while co-doping with Ca2+ was done to enhance the luminescence of the activatorTm3+.NOrelease from SNAP was triggered by an NIR-UV up-conversion process, initiated by 808nmlight absorbed by the Nd3+ ions.NOrelease was confirmed by the Griess method. Under 808nmirradiation, the viability of the liver cancer cell line HepG2 significantly decreased with increasing UCNPs@mSiO2-SNAP concentration. For a UCNPs@mSiO2-SNAP concentration of 200 μgml−1, the cell survival probability was 47%. These results demonstrate that UCNPs@mSiO2-SNAP can induce the release of apoptosis-inducingNOby NIR irradiation. KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Brightness KW - NIR KW - Mechanism KW - Triggered KW - Release KW - Cell KW - PDT KW - Dye KW - Therapy KW - Surface KW - Coating PY - 2022 DO - https://doi.org/10.1088/2050-6120/ac5524 VL - 10 IS - 2 SP - 1 EP - 9 PB - IOP Publishing AN - OPUS4-54842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Srivastava, Priyanka T1 - Multi-color nanosensors for ratiometric measurements of acidic, neutral, and basic pH based on silica and polystyrene particles N2 - pH presents one of the most important analytes in the life and material sciences, indicating, e.g., diseases and corrosion processes. This includes the optical monitoring of pH in living cells for studying cellular internalization pathways, such as phagocytosis, endocytosis, and receptor mediated internalization with the aid of molecular and nanoscale fluorescent sensors. Nanoparticle (NP)-based sensors, that are labelled or stained with a multitude of sensor dyes, have several advantages as compared to conventional molecular probes like enhanced brightness, i.e., amplified signals, ease of designing ratiometric systems by combining analyte-sensitive and inert reference dyes, and increased photostability. Moreover, this can enable the use of hydrophobic dyes in aqueous environments. Versatile templates and carriers for the fabrication of nanosensors by staining and/or labelling with different fluorophores and sensor molecules are surface-functionalized particles like silica (SiO2) and polystyrene (PS) particles. Here we present a platform of blue-red-green fluorescent pH nanosensors for the measurement of acidic, neutral, and basic pH utilizing both types of matrices and two spectrally distinguishable sensor dyes with an integrated reference dye and demonstrate its applicability for cellular studies. T2 - E-MRS Spring Meeting 2022 CY - Online meeting DA - 30.05.2022 KW - Nanosensors KW - pH sensing KW - Silica- and polystyrene particles KW - Ratiometric sensors KW - Fluorescence PY - 2022 AN - OPUS4-55597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - van Wasen, S. A1 - You, Yi A1 - Beck, S. A1 - Riedel, Jens A1 - Volmer, D. A. T1 - Laser Ablation Secondary Electrospray Ionization for In Situ Mass Spectrometric Interrogation of Acoustically-Levitated Droplets N2 - The composition of acoustically levitated droplets was probed by a novel combination of mid-IR laser evaporation and subsequent postionization via secondary electrospray ionization. The combination of microliter samples and subnanoliter sampling provided time-resolved interrogation of droplets and allowed for a kinetic investigation of the laser-induced release of the analyte, which was found to strongly depend on the analytes. The observed substancespecific delayed release of the analytes permitted baseline-separated discrimination of the analytes, ideal for the study of complex samples. The additionally applied postionization scheme was found to enable efficient detection of small volatile compounds as well as peptides. The detection of small molecules and peptides occurred under very different sampling geometries, pointing to two distinct underlying ionization mechanisms. Overall, our results suggest that the experimental setup presented in this study can serve as a widely applicable platform to study chemical reactions in acoustically levitated droplets as model reactors. KW - Acoustic levitation KW - Mass spectrometry KW - Electrospray KW - Laser ablation PY - 2022 DO - https://doi.org/10.1021/acs.analchem.2c03800 SN - 0003-2700 VL - 2022 SP - 1 EP - 5 PB - ACS Publications CY - Washington AN - OPUS4-56531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishurova, Tatiana T1 - In-situ imaging of additively manufactured alloys at the BAMline N2 - In this work, we present the recent in-situ imaging developments at the BAMline (of synchrotron BESSY II, HZB), focused on the in-situ characterization and understanding of microstructural evolution of additively manufactured materials subjected to different environments. Two show cases are presented. In the first, X-ray refraction radiography (SXRR) was combined with in-situ heat treatment to monitor the microstructural evolution as a function of temperature in a laser powder bed fusion (LPBF) manufactured AlSi10Mg alloy. We show that SXRR allows detecting the changes in the Si-phase morphology upon heating using statistically relevant volumes. SXRR also allows observing the growth of pores (i.e., thermally induced porosity), usually studied via X-ray computed tomography (XCT), but using much smaller fields-of-view. In the second case study, XCT was combined with in-situ tensile test to investigate the damage mechanism in a LPBF Aluminum Metal Matrix Composite (MMC). In-situ SXCT test disclosed the critical role of the defects in the failure mechanism along with pre-cracks in the reinforcement phase of MMC. We found that cracks were initiated from lack-of-fusion defects and propagated through coalescence with other defects. T2 - New Frontiers in Materials Design for Laser Additive Manufacturing CY - Montabaur, Germany DA - 22.05.22 KW - Additive manufacturing KW - Laser powder bed fusion KW - Synchrotron X-ray computed tomography KW - Synchrotron X-ray Refraction PY - 2022 AN - OPUS4-54900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishurova, Tatiana A1 - Evsevleev, Sergei A1 - Mehta, B. A1 - Nyborg, L. A1 - Virtanen, E. A1 - Markötter, Henning A1 - Hryha, E. A1 - Bruno, Giovanni T1 - Failure Mechanisms Investigation by Means of in-situ Synchrotron Computed Tomography in Aluminum MMC-based Alloy Tailored for Additive Manufacturing (AM) N2 - The availability of high-performance Al alloys in AM is limited due to difficulties in printability, requiring both the development of synergetic material and AM process to mitigate problems such as solidification cracking during laser powder bed fusion (LPBF). The goal of this work was to investigate the failure mechanism in a LPBF 7017 Aluminium alloy + 3 wt% Zr + 0.5 wt% TiC. The processing leads to different categories of Zr-rich inclusions, precipitates and defects. T2 - Alloys for Additive Manufacturing Symposium 2022 (AAMS22) CY - Munich, Germany DA - 11.09.2022 KW - Additive manufacturing KW - Laser powder bed fusion KW - Synchrotron X-ray computed tomography KW - MMC PY - 2022 AN - OPUS4-56110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Reliable, and reproducible physico-chemical data of nanomaterials for risk assessment N2 - Nanoforms with at least one dimension below 100 nm have an important part to play in more and more areas of our daily life. Therefore, risk assessment of these materials is becoming increasingly important. In this context, the European Chemical Agency (ECHA) considered eleven physico-chemical properties as relevant, of which the following six are essential for the registration: chemical composition, crystallinity, particle size, particle shape, surface chemistry and specific surface area. Four of these priority properties can be obtained with electron microscopy and surface analytics like XPS and ToF-SIMS. The reliability of this data must be ensured, especially for their use for grouping and read across approaches. On the other hand, the “reproducibility” crisis has revealed major shortcomings in the reliability of published data. In a case study, we show how the quality of the data can be ensured by using existing standards and protocols of each step in the workflow of sample characterization. As exemplary samples, two Al-coated TiO2 samples as nanopowders were selected from the JRC repository, capped either with a hydrophilic or a hydrophobic organic ultrathin shell. SEM results provided the size and shape of the nanoparticles, a first overview about the composition was obtained with EDS. XPS and ToF-SIMS supplied the surface chemistry, especially information about the shell and the coating of the particles. Standards and protocols of all steps of the analytical workflow including preparation and data reduction are discussed regarding reliable and reproducible data. Additionally, uncertainties for the different steps are specified. Only such a detailed description of all these factors allows a comprehensive physico-chemical characterization of the nanoparticles with understanding of their potential risk assessment. T2 - ECASIA 2022 CY - Limerick, Ireland DA - 29.05.2022 KW - Reference data KW - Risk assessment KW - Nanomaterials KW - Titania PY - 2022 AN - OPUS4-54961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - VAMAS ILC of functionalized Graphene by XPS and Graphene Oxide by SEM N2 - The ideas of the planned VAMAS interlaboratory comparisons of functionalized graphene and graphene oxide are presented. T2 - Stakeholder Advisory Board ISO-G-Scope CY - Online meeting DA - 12.01.2022 KW - Graphene KW - XPS KW - SEM PY - 2022 AN - OPUS4-54375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hahn, Marc Benjamin T1 - BioSAXS models for TOPAS/Geant4 N2 - Models for TOPAS/Geant4 to estimate the microscopic dose received by biomolecules during bioSAXS experiments. The C++ classes in this repository extend the functionality of the TOPAS (http://www.topasmc.org/) Monte-Carlo program, which is itself a wrapper of the Geant4 MCS Toolkit (http://geant4.org). KW - TOPAS KW - TOPAS-nBio KW - Geant4 KW - Geant4-DNA KW - MCS KW - Microdosimetry KW - Protein KW - Proteins KW - Particle scattering KW - G5P KW - GV5 KW - SAXS KW - Monte-Carlo simulation KW - Dosimetry KW - Micorscopic dose-damage relation PY - 2022 UR - https://github.com/MarcBHahn/TOPAS-bioSAXS-dosimetry DO - https://doi.org/10.26272/opus4-55751 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-55751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Detection of aluminum deposition on the cathodes of aged lithium ion batteries by GD-OES N2 - The use of renewable energy sources, electromobility, and portable electronics relies on lithium-ion batteries (LIBs). However, one detrimental effect, which can result in significant performance loss, is the corrosion of the current collectors caused by the aging mechanisms, especially in high-energy-density batteries Glow discharge optical emission spectroscopy (GD-OES) provides depth profile analysis through sputtering using argon plasma, which enables the analysis of the corrosion behavior at different depths of the cathodes. T2 - GD-OES Anwendertreff CY - Dresden, Germany DA - 26.27.2022 KW - glow KW - discharge KW - optical KW - emission KW - spectroscopy PY - 2022 AN - OPUS4-56105 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moufid, M. A1 - Tiebe, Carlo A1 - El Bari, N. A1 - Bartholmai, Matthias A1 - Bouchikhi, B. T1 - Advance in electronic nose technology developed for the detection and discrimination of ethanol, ammonia, and hydrogen sulfide gases N2 - This work focuses on the design and fabrication of low-cost and fast-response of an electronic nose (E-nose) based on semiconductor gas sensors, for discriminating some synthetic gases such as ammonia (NH3), ethanol (C2H5OH), and hydrogen sulfide (H2S). Additionally, the capability of separating different concentration levels of each considered gases was checked. Dataset treatment of E-nose by using Principal Component Analysis (PCA) showed a good discrimination of the different synthetic gases. Furthermore, perfect classification was reached of different concentration levels of the analysed gases by using Discriminant Function Analysis (DFA). In the light of these results, it could be stated that the developed E-nose system constitutes an inexpensive, rapid, simple to use, and efficient tool for synthetic gases detection. T2 - IEEE International Symposium on Olfaction and Electronic Nose (ISOEN) CY - Aveiro, Portugal DA - 29.05.2022 KW - Electronic nose KW - Metal oxide semiconductor KW - Chemometric techniques KW - Environmental analysis PY - 2022 SN - 978-1-6654-5860-3 DO - https://doi.org/10.1109/ISOEN54820.2022.9789636 SP - 1 EP - 3 AN - OPUS4-56574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moufid, M. A1 - Tiebe, Carlo A1 - El Bari, N. A1 - Hamada, D. A. A1 - Bartholmai, Matthias A1 - Bouchikhi, B. T1 - Pollution parameters evaluation of wastewater collected at different treatment stages from wastewater treatment plant based on E-nose and E-tongue systems combined with chemometric techniques N2 - Wastewater contains harmful chemicals and heavy metals that are known to cause various environmental and health problems. Therefore, the water quality control using sensitive, simple, fast, accurate, and portable tools is of great importance. This study aimed to evaluate the pollution parameters of wastewaters collected at different treatment stages from a wastewater treatment plant (WWTP) that treats domestic and industrial wastewaters by using an electronic nose (E-nose) and a voltammetric electronic tongue (E-tongue) combined with chemometric techniques. Water and wastewater pollution parameters determination were performed using inductively coupled plasma optical emission spectrometry for the determination of cations, and anions by using ion chromatography. Chemometric techniques, such as Principal Component Analysis (PCA), Discriminant Function Analysis (DFA), Support Vector Machines (SVMs), and Hierarchical Cluster Analysis (HCA), were used to process the E-nose and E-tongue datasets to describe the similarities between the samples. In addition, Partial Least Squares Regression (PLSR) model was constructed using electronic sensing data to simultaneously predict the concentration values of physicochemical parameters. The obtained correlation coefficient, for training and testing sets, is higher than 0.91 for the prediction of the concentration of all physicochemical parameters, except for iron (Fe) which remains 0.84. These results suggest that simple, portable, and inexpensive tools such as electronic nose and tongue are suitable for wastewater analysis. KW - Wastewater KW - Electronic nose KW - Voltammetric electronic tongue KW - Water quality control KW - Chemometric techniques KW - Gas sensing PY - 2022 DO - https://doi.org/10.1016/j.chemolab.2022.104593 VL - 227 SP - 1 EP - 12 PB - Elsevier B.V. AN - OPUS4-55652 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pollard, M. T1 - Functionalized Poly(ethylene glycol)s (PEGs) as a Reference Material for Detection of Polymeric end Groups via SEC Hyphenated with FTIR and 1H-NMR (80 MHz) N2 - With the online coupling (or hyphenation) of chemically-resolved spectroscopy detection with classical size-exclusion chromatography (SEC) it is possible to correlate polymer molecular size with chemical structure in a single in-situ or on-flow measurement. Medium-resolution 1H-NMR (60 MHz) spectroscopy (i.e., “desktop NMR”) and Fouriertransform Infrared Spectroscopy (FTIR) have both been developed as coupled methods (SEC-MR-NMR, SEC-FTIR) for the detection of polymer analytes by monitoring e.g. alkene or carbonyl functionality.1,2 Here, we have investigated the potential for the detection of polymer end groups, using a slightly higher field-strength spectrometer (80 MHz 1H Larmor frequency) and taking advantage of a columnless injection method that provides bulk spectra for reference. End-functionalized polymers were synthesized by reaction of PEG with toluene isocyanate, yielding ,-functionalized polymers with exactly 2 IR- and NMR-detectable functional groups per chain, as proven by MALD-TOF mass spectrometry. We have investigated the sensitivity (limit of detection) and spectral resolution for these functional groups in chloroform, THF, and water. Results have demonstrated a good feasibility for the simultaneous online detection of PEG backbone (M~4000 g/mol) and these end groups at the level of ca. 2 mol%. T2 - 33rd International Symposium on Chromatography CY - Budapest DA - 18.09.2022 KW - Size exclusion chromatography KW - Polyethyleneglycol KW - MALDI-TOF MS KW - NMR PY - 2022 AN - OPUS4-56716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria T1 - Size-Tunable Ni-Cu Core-Shell Nanoparticles: Structure, Composition, and Catalytic Activity N2 - Nanoparticles (NPs) have become important materials for a variety of chemical technologies, including catalysis. One of the main challenges is the reduction of green house gases, such as CO2. One opportunity besides the capturing is the conversion to synthesis gas via the reverse water-gas shift reaction. A facile and efficient method is described for the solvothermal synthesis of size-tunable, stable, and uniform NiCu core-shell NPs. The diameter of the NPs can be tuned in a range from 6 nm to 30 nm and the Ni:Cu ratio from 30:1 to 1:1. The NPs are structurally characterized with combination of transmission electron microscopy, anomalous small-angle X-ray scattering, X-ray photoelectron spectroscopy, and X-ray absorption fine structure. Using these analytical methods, a core-shell-shell structure their chemical composition is elucidated. A depletion from the core to the shell is observed, with the core consisting of NiCu alloy, surrounded by an inner Ni-rich shell and an outer NiO shell. The SiO2-supported NiCu core-shell NPs show pronounced selectivity of >99% for CO in the catalytic reduction of CO2 to CO using hydrogen as reactant (reverse water–gas shift reaction). T2 - Nanoalloys: recent developments and future perspectives Faraday Discussion CY - London, UK DA - 21.09.2022 KW - Nanoparticles KW - Core-shell KW - Catalysis PY - 2022 AN - OPUS4-56831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fritzsche, Sven T1 - Classification of defects in Direct Laser Writing N2 - Direct laser writing grows to an industry-ready manufacturing platform. A stable quality infrastructure is needed for robust processing. However, flaws, errors or impurities are neither described nor communicated in the community of two-photon polymerization. In contrast, additive manufacturing errors in metals manufacturing are described thoroughly. T2 - MNE EUROSENSORS 2022 CY - Leuven, Belgium DA - 19.09.2022 KW - Quality infrastructure KW - Direct laser writing KW - Two photon polymerisation PY - 2022 AN - OPUS4-55984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Morpho-Chemical Characterisation of Me-TiO2 Nanoparticles for Enhanced Photocatalytical Activity N2 - The conversion of solar energy into electricity and solar fuels is of crucial importance for a green and sustainable future. Water splitting using semiconductor photo-catalysts is considered a sustainable method to produce clean hydrogen (H2) fuel. Nevertheless, H2 photo-production efficiency remains still low, although extensive research works to understand better the mechanisms of the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are being carried out. In this respect, TiO2 is a key photoactive material, usually employed with a co-catalyst deposited onto the surface to enhance charge carriers’ separation and catalyze surface charge transfer reactions. The deposition of a co-catalyst on the TiO2 nanoparticle surface represents one successful way to enhance the activity of the photocatalyst through a modification of its surface and redox properties. In this context, high-resolution scanning electron microscopy coupled with elemental analysis by energy-dispersive X-ray spectroscopy (EDS) is fundamental for studying and understanding the effect of the nanoparticle morphology on the functional properties of shape-controlled TiO2 crystals (bipyramides, platelets, and elongated particles). Different types of metal-semiconductor combinations, TiO2 shapes and dopant metals (Ag, Pt, etc) and metal concentrations will be discussed. T2 - ECASIA 2022 CY - Limerick, Ireland DA - 29.05.2022 KW - Titania nanoparticles KW - Photocatalysis KW - Scanning electron microscopy KW - Energy dispersive X-ray spectroscopy PY - 2022 AN - OPUS4-54977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B.P. A1 - Radnik, Jörg A1 - Shard, A.G. T1 - Ionic liquid [PMIM]+[NTf2]− (Solarpur®) characterized by XPS N2 - X-ray photoelectron spectroscopy (XPS) was performed on the meniscus of a droplet of ionic liquid 1-propyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl) imide [PMIM]+[NTf2]− (Solarpur®) in ultrahigh vacuum. High-resolution spectra of F 1s, O 1s, N 1s, C 1s, and S 2p are presented along with a survey spectrum and the valence band structure. The spectra presented here were generated using monochromatic Al Kα radiation (1486.6 eV). KW - Ionic liquid KW - 1-propyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide KW - X-ray Photoelectron Spectroscopy PY - 2022 DO - https://doi.org/10.1116/6.0001518 VL - 29 IS - 1 SP - 014001-1 PB - AVS AN - OPUS4-54335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - VAMAS-Enabling international standardisation for increasing the take up of Emerging Materials N2 - VAMAS (Versailles Project on Advanced Materials and Standards) supports world trade in products dependent on advanced materials technologies by providing technical basis for harmonized measurements, testing, specification, reference materials and standards. The major tools for fulfilling this task are interlaboratory comparisons (ILC). The organisation structure of VAMAS is presented. It is discussed, how a new technical activity can initiate. T2 - DIN NA062-08-16 Oberflächenanalytik Frühjahrstreffen CY - Berlin, Germany DA - 11.05.2022 KW - Advanced Materials KW - Standards KW - Interlaboratory Comparisons PY - 2022 AN - OPUS4-54831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - ISO-G-Scope Standardisation of structural and chemical properties of graphene N2 - The objectives and tasks of the EMPIR project ISO-G-Scope are presented. The last results was shown. Esspecially, the interlaboratory comparison about XPS of functionalized graphene is presented. T2 - DIN NA062-08-16 Oberflächenanalytik Frühjahrstreffen CY - Berlin, Germany DA - 11.05.2022 KW - Graphene KW - Standardization KW - Structural characterisation KW - Chemical composition PY - 2022 AN - OPUS4-54834 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Colours, nano and surface N2 - The basic ideas of colours and pigments are presented. The correlation between nanomaterials and colours are explained. Different methods are presented for investigating nanoparticles and their surface. At the end a case study is presented explaining the importance of coating for the properties of nanoparticles. T2 - Eingeladener Vortrag im Deutschen Lackmuseum (Münster) CY - Online meeting DA - 11.02.2022 KW - Pigments KW - Surface Analytics KW - Coatings PY - 2022 AN - OPUS4-54376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Energy-resolved x-ray photoelectron spectroscopy measurements on the concentration profile of thin blended poly(vinyl methyl ether)/polystyrene films N2 - The composition of thin films of polymer blends in vertical direction is still under discussion. For explaining the thickness dependence of some properties like the thermal glass transition temperature, a three-layer model has been introduced consisting of an adsorbed layer with a reduced segmental mobility at the substrate, a bulk-like layer in the middle of the film and an outermost surface layer with a higher molecular mobility. X-ray photoelectron spectroscopy (ER-XPS) measurements with a varying excitation energy from 400 eV to 1486.6 eV and, herewith, an information depth from 1.5 nm to 10 nm were performed at PVME/PS films with compositions of 25/75 wt% and 50/50 wt% and thicknesses between 15 nm and 190 nm. As expected, it was found that the PVME concentration decreases with increasing information depth. Secondly, a complex correlation between the PVME concentration at the surface and the film thickness was found. The PVME concentration increases with decreasing film thickness until a maximum at 30 nm. For thinner films, the PVME concentration decreases. These data agree with previous investigations obtained with specific heat spectroscopy. We thank BESSY II (HZB) for the allocation of beamtime at the HE-SGM beamline and for technical support. DFG (Project number 124846229) is acknowledged for financial support. T2 - German Conference for Research with Synchrotron Radiation, Neutrons and Ion Beams at Large Facilities (SNI2022) CY - Berlin, Germany DA - 05.09.2022 KW - X-ray photoelectron spectroscopy KW - Miscible polymer films KW - Depth profiling PY - 2022 AN - OPUS4-55654 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hallier, Dorothea C. T1 - An XPS study on X-ray radiation damage: Chemical changes to Gene-V Protein of Bacteriophage M13 N2 - X-ray photoelectron spectroscopy (XPS) is used to analyze the direct damage of ionizing radiation to a single-stranded DNA binding protein: Gene-V Protein (G5P). T2 - Science Day Uni Potsdam Institut für Biochemie und Biologie CY - Potsdam, Germany DA - 11.10.2022 KW - XPS KW - Radiaton damage KW - G5P GVP KW - Single-stranded DNA-binding protein KW - X-ray KW - DNA PY - 2022 AN - OPUS4-56541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Standardized workflow for checking the performance of an EDS X-ray spectrometer at a Scanning Electron Microscope N2 - For test laboratories operating under accreditation schemes like ISO/IEC 17025 (ISO/IEC 17025), as the international reference for testing and calibration laboratories wanting to demonstrate their capacity to deliver reliable results, a periodical control of the critical instrumental parameters of an Energy-Dispersive X-ray Spectrometer (EDS) is required. This periodical check of an EDS is specified with exact procedures and materials in the ISO 15632:2021 ”Microbeam Analysis – Selected instrumental performance parameters for the specification and checking of energy-dispersive X-ray spectrometers for use in electron probe microanalysis” (ISO 15632). The EDS check can be simplified to the acquisition of only one 10 kV spectrum from a dedicated test material, EDS-TM002, which is made available by BAM since 2009 (https://webshop.bam.de/webshop_en/). The optional BAM software “EDX spectrometer check” is destined to automatically evaluate this spectrum and determine the performance of the EDS in terms of energy resolution and calibration, as well as possible alteration of low-energy efficiency due to detector contamination. Nearly 200 laboratories have the EDS-TM and associated software package in use. Practical examples based on various types of artifacts occurred in the EDS spectra and a long-term (>10 years) meticulous observation of the own spectrometers will be discussed. Different types of EDS spectrometers are considered, e.g. Si(Li) and SDD, of various window types (AP, the recent one Si3N4 or even windowless), and with different front contact layers (Au and Ni) (Hodoroaba and Procop, 2014). Evaluation of other parameters or effects such as the deadtime at different count rates or pileup effects is also explained with examples. T2 - Workshop "Automated Mineralogy" @ GEOANALYSIS 2022 CY - Freiberg, Germany DA - 06.08.2022 KW - EDS KW - X-ray spectrometer KW - Performance check KW - Test material KW - Standardized check KW - EDS-TM002 PY - 2022 UR - https://geoanalysis2021.de/en/workshops/automated-mineralogy AN - OPUS4-55460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Explaining Deviatoric Residual Stresses and Load Transfer in Aluminum Alloys and Composites with Complex Microstructure N2 - The residual stresses and load transfer in multiphase metal alloys and their composites (with both random planar-oriented short fibers and particles) will be shown, as studied by neutron diffraction, by X-ray computed tomography, and by a model based on the reformulation of classic Maxwell’s homogenization method. Contrary to common understanding and state-of-the-art models, we experimentally observe that randomly oriented phases possess non-hydrostatic residual stress. Moreover, we disclose that the unreinforced matrix alloy stays under hydrostatic compression even under external uniaxial compression. The recently developed modeling approach allows calculating the residual stress in all phases of the composites. It rationalizes the presence of deviatoric stresses accounting for the interaction of random oriented phases with fibers having preferential orientation. It also allows the explanation of the unconventional in-situ behavior of the unreinforced alloy and the prediction of the micromechanical behavior of other similar alloys. T2 - MLZ Konferenz 2022 CY - Lenggries, Germany DA - 31.05.2022 KW - Residual Stresses KW - Aluminium Alloys KW - Microstructures PY - 2022 AN - OPUS4-55020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Miropoltsev, M. A1 - Wegner, Karl David A1 - Häusler, I. A1 - Hodoroaba, Vasile-Dan A1 - Resch-Genger, Ute T1 - Influence of Hydrophilic Thiol Ligands of Varying Denticity on the Luminescence Properties and Colloidal Stability of Quaternary Semiconductor Nanocrystals N2 - Binary photoluminescent semiconductor nanocrystals (quantum dots, QDs) are one of the best studied fluorescent nanomaterials, and their unique optoelectronic properties paved the road to many applications in (bio)nanophotonics, optoelectronics, and photovoltaics. However, concerns related to their toxic constituents like cadmium or lead and the emerging interest in greener chemistry synthesis approaches hamper their future applicability. Interesting alternatives for some applications like biosensing or bioimaging are heavy-metal-free ternary QDs like AgInS2 (AIS), CuInS2 (CIS), and quaternary QDs such as AIS-ZnS (ZAIS). In this context, we explored the effect of ligand denticity on the organic-to-aqueous phase transfer of oleylamine-stabilized ZAIS QDs with the hydrophilic ligands mercaptopropionic acid (MPA), dihydrolipoic acid (DHLA), and 3-mercapto-2,2-bis(mercaptomethyl)propanoic acid (3MPA), bearing mono-, bi-, and trialkyl thiol groups. Spectroscopic studies of the resulting water-dispersible ZAIS QDs revealed a considerable influence of ligand denticity and ligand-to-QD ratio on the spectral position and width (FWHM; full width at half-maximum) of the photoluminescence (PL) bands, the PL quantum yields (PL QY), and the PL decay kinetics. Thiol capping and phase transfer resulted in a loss in PL by at least a factor of 2. The ligand-induced PL quenching observed particularly for ligands bearing two or three thiol groups was attributed to the facilitated formation of surface-bound disulfides. The best colloidal stability under high dilution conditions was observed for 3MPA. KW - Quantum dots KW - Ligand exchange KW - Lifetime analysis KW - Thiols PY - 2022 DO - https://doi.org/10.1021/acs.jpcc.2c05342 SN - 1932-7447 VL - 126 IS - 47 SP - 20101 EP - 20113 PB - ACS Publications AN - OPUS4-56707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Elemental Composition and Thickness Determination of Thin Films by Electron Probe Microanalysis (EPMA) N2 - microscopy (AFM), or X-ray reflectometry. For the additional determination of thin film composition, techniques like X-ray photoelectron spectroscopy (XPS) or mass spectrometry-based techniques can be used. An alternative non-destructive technique is electron probe microanalysis (EPMA). This method assumes a sample of homogenous (bulk) chemical composition, so that it cannot be usually applied to thin film samples. However, in combination with the thin film software StrataGEM, the thickness as well as the composition of such films on a substrate can be determined. This has been demonstrated for FeNi on Si and SiGe on Al2O3 film systems. For both systems five samples with different elemental composition and a reference were produced and characterised by Korean research institute KRISS using inductively coupled plasma mass spectrometry (ICP-MS), Rutherford backscattering (RBS), and transmission electron microscopy (TEM). These samples were used for an international round robin test. In 2021, a new and open-source thin film evaluation programme called BadgerFilm has been released. It can also be used to determine thin film composition and thickness from intensity ratios of the unknown sample and standards (k-ratios). In this contribution, we re-evaluated the data acquired for the FeNi and SiGe systems using the BadgerFilm software package and compared the resulting composition and thickness with the results of the established StrataGEM software and other reference methods. With the current evaluation, the BadgerFilm software shows good agreement with the composition and thickness calculated by StrataGEM and as the reference values provided by the KRISS. T2 - ECASIA 2022 CY - Limerick, Ireland DA - 29.05.2022 KW - Thin films KW - Electron Probe Microanalysis KW - Interlaboratory Comparisons PY - 2022 AN - OPUS4-54963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riedel, Soraya T1 - Application of 3,3’,5,5’-Tetramethylbenzidine (TMB) in Amperometric Immunoassays for Mycotoxin Detection N2 - Electrochemical methods make great promise to meet the demand for user-friendly on-site devices for monitoring important parameters. Food industry often runs own lab procedures, e.g., for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with miniaturized technologies. Enzyme-linked immunosorbent assays, with photometric detection of the horseradish peroxidase (HRP) substrate 3,3’,5,5’-tetramethylbenzidine (TMB), form a good basis for sensitive detection. To provide a straight-forward approach for the miniaturization of the detection step, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry, it could be shown that TMB electrochemistry is strongly dependent on the pH and the electrode material. It was found that screen-printed gold electrodes and a very low pH value (pH 1) are well-suited to perform the electrochemical detection of TMB, due to the reversible character of the redox reaction under these conditions. Under these conditions, a good signal stability over several measuring cycles is achieved, providing the basis for analyzing multiple samples. In contrast to this, for carbon screen-printed electrodes, it was found that the signal response has changed after the electrochemical reaction with TMB at pH 1. At moderately acidic conditions (pH 4), neither with carbon nor with gold electrodes a reproducible electrochemical detection of TMB could be achieved. Based on these findings, we created a smartphone-based, electrochemical, immunomagnetic assay for the detection of ochratoxin A (OTA) and ergometrine in food samples. A competitive assay is performed on magnetic beads using HRP and TMB/H2O2 to generate the signal. Enzymatically oxidized TMB is quantified after addition of H2SO4 by amperometry with screen-printed gold electrodes in a custom-made wall-jet flow cell. The results are in good correlation with the established photometric detection method, providing a solid basis for sensing of further analytes in HRP-based assays using the newly developed miniaturized smartphone-based, electrochemical, immunomagnetic assay. T2 - 73rd Annual Meeting of the ISE CY - Online meeting DA - 12.09.2022 KW - Cylic Voltammetry KW - Immunoassay KW - Mycotoxins KW - Amperometry KW - Electrochemistry PY - 2022 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. AN - OPUS4-55793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul T1 - The Role of Electron Microscopy in the Development of Monodisperse Cubic Iron Oxide Nanoparticles as CRM for Size and Shape N2 - Due to their unique physico-chemical properties, nanoparticles are well established in research and industrial applications. A reliable characterization of their size, shape, and size distribution is not only mandatory to fully understand and exploit their potential and develop reproducible syntheses, but also to manage environmental and health risks related to their exposure and for regulatory requirements. To validate and standardize methods for the accurate and reliable particle size determination nanoscale reference materials (nanoRMs) are necessary. However, there is only a very small number of nanoRMs for particle size offered by key distributors such as the National Institute of Standards and Technology (NIST) and the Joint Research Centre (JRC) and, moreover, few provide certified values. In addition, these materials are currently restricted to polymers, silica, titanium dioxide, gold and silver, which have a spherical shape except for titania nanorods. To expand this list with other relevant nanomaterials of different shapes and elemental composition, that can be used for more than one sizing technique, we are currently building up a platform of novel nanoRMs relying on iron oxide nanoparticles of different shape, size and surface chemistry. Iron oxide was chosen as a core material because of its relevance for the material and life sciences. T2 - Microscopy and Microanalysis 2022 CY - Online meeting DA - 31.07.2022 KW - Certified Referencematerial KW - Cubical Iron Oxide KW - Nanoparticles KW - Electron Microscopy KW - Small-Angle X-ray Scattering PY - 2022 AN - OPUS4-57035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - ToF-SIMS at advanced materials - from nano to energy N2 - The basic principles of ToF-SIMS will be explained. Examples of the use of ToF-SIMS for the investigation of titania and core-shell nanoplastic will be given. Furhtermore, 3d reconstruction is explained for nanoparticle research and energy-related materials. T2 - BUA Summer School Mass Spectrometry CY - Berlin, Germany DA - 04.10.2022 KW - ToF-SIMS KW - Nanomaterials KW - Imaging PY - 2022 AN - OPUS4-55897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -