TY - JOUR A1 - Lange, Nele A1 - Dietrich, Paul M. A1 - Lippitz, Andreas A1 - Kulak, N. A1 - Unger, Wolfgang T1 - New azidation methods for the functionalization of silicon nitride and application in copper-catalyzed azide-alkyne cycloaddition (CuAAC) N2 - In this study, a new direct functionalization method of silicon nitride (Si3N4) using azidation and click chemistry is presented. First, amino groups (NHx) were created on a Si3N4 substrate by fluoride etching. These NHx-terminated Si3N4 surfaces were analyzed by chemical derivatization X-ray photoelectron spectroscopy (CD-XPS) with 4-trifluoromethylbenzaldehyde (TFBA) and a derivatization yield of 20% was concluded. In the second step freshly prepared NHx surfaces were transformed into azides which were used immediately in a click reaction with halogenated alkynes. The presented combination of amination, azidation and click reaction is a promising alternative for common silane-based Si3N4 functionalization methods. T2 - 16th European Conference on Applications of Surface and Interface Analysis CY - Granada, Spain DA - 28.09.2015 KW - XPS KW - Azidation KW - Click chemistry KW - Silicon nitride KW - Chemical derivatization PY - 2016 UR - http://onlinelibrary.wiley.com/doi/10.1002/sia.5950/full U6 - https://doi.org/10.1002/sia.5950 VL - 48 SP - 621 EP - 625 PB - John Wiley & Sons, Ltd AN - OPUS4-36841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Swaraj, S. A1 - Dietrich, Paul M. T1 - X-ray spectromicroscopy of nanoparticulate iron oxide phases N2 - Soft x-ray spectromicroscopy techniques have seen great amount of development in the recent years, and with the development of new diffraction limited synchrotron source, many new nanoscale and mesoscale characterization opportunities of applied materials are foreseen. In this perspective, the authors present some examples that illustrate the capabilities of spectromicroscopy techniques, namely, 2D and 3D spatially resolved chemical quantification, surface and bulk sensitive measurements, and polarization dependent measurements as applied to iron oxide nanoparticulate materials of biological, geological, and other origins. KW - X-ray spectromicroscopy KW - STXM KW - Iron oxide PY - 2016 U6 - https://doi.org/10.1116/1.4966654 SN - 1934-8630 SN - 1559-4106 VL - 11 IS - 4 SP - 04B402-1 EP - 04B402-6 PB - AVS: Science & Technology of Materials, Interfaces, and Processing AN - OPUS4-38274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Belsey, N. A. A1 - Cant, D. J. H. A1 - Minelli, C. A1 - Araujo, J. R. A1 - Bock, B. A1 - BrĂ¼ner, P. A1 - Castner, D. G. A1 - Ceccone, G. A1 - Counsell, J. D. P. A1 - Dietrich, Paul M. A1 - Engelhardt, M. H. A1 - Fearn, S. A1 - Galhardo, C. E. A1 - Kalbe, H. A1 - Kim, J. W. A1 - Lartundo-Rojas, L. A1 - Luftman, H. S. A1 - Nunney, T. S. A1 - Pseiner, J. A1 - Smith, E. F. A1 - Spampinato, V. A1 - Sturm, J. M. A1 - Thomas, A. G. A1 - Treacy, J. P. W. A1 - Veith, L. A1 - Wagstaffe, M. A1 - Wang, H. A1 - Wang, M. A1 - Wang, Y.-C. A1 - Werner, W. A1 - Yang, L. A1 - Shard, A. G. T1 - Versailles Project on Advanced Materials and Standards Interlaboratory Study on Measuring the Thickness and Chemistry of Nanoparticle Coatings Using XPS and LEIS N2 - We report the results of a Versailles Project on Advanced Materials and Standards (VAMAS) interlaboratory study on the measurement of the shell thickness and chemistry of nanoparticle coatings. Peptide-coated gold particles were supplied to laboratories in two forms: a colloidal suspension in pure water and particles dried onto a silicon wafer. Participants prepared and analyzed these samples using either X-ray photoelectron spectroscopy (XPS) or low energy ion scattering (LEIS). Careful data analysis revealed some significant sources of discrepancy, particularly for XPS. Degradation during transportation, storage, or sample preparation resulted in a variability in thickness of 53%. The calculation method chosen by XPS participants contributed a variability of 67%. However, variability of 12% was achieved for the samples deposited using a single method and by choosing photoelectron peaks that were not adversely affected by instrumental transmission effects. The study identified a need for more consistency in instrumental transmission functions and relative sensitivity factors since this contributed a variability of 33%. The results from the LEIS participants were more consistent, with variability of less than 10% in thickness, and this is mostly due to a common method of data analysis. The calculation was performed using a model developed for uniform, flat films, and some participants employed a correction factor to account for the sample geometry, which appears warranted based upon a simulation of LEIS data from one of the participants and comparison to the XPS results. KW - VAMAS KW - Interlaboratory Study KW - Nanoparticle coating KW - XPS KW - LEIS KW - shell thicknss and chemistry PY - 2016 UR - http://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.6b06713 U6 - https://doi.org/10.1021/acs.jpcc.6b06713 IS - 120 SP - 24070 EP - 24079 PB - ACS Publications AN - OPUS4-38428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul M. A1 - Lange, Nele A1 - Lippitz, Andreas A1 - Holzweber, Markus A1 - Kulak, N. A1 - Unger, Wolfgang T1 - Click chemistry on silicon nitride for biosensor fabrication N2 - Biosensors are of essential importance in medical and biological diagnostics. Often, they are produced using silane chemistry on glass or silicon oxide surfaces. However, controlling that silane chemistry is challenging. Here, we present an alternative strategy to form functional organic layers and biosensors on silicon Nitride (Si3N4). H-terminated Si3N4 films are used to generate reactive azide groups by various azidation methods. Biomolecular probes can then be immobilized using click chemistry reactions with the azide groups and due to its high sensitivity in XPS a fluorine-substituted test alkyne was utilized to optimize click chemistry conditions. After that a biotinylated alkyne was clicked to Si3N4 surfaces followed by immobilization of streptavidin as analyte in a model assay. The functionalized surfaces were thoroughly characterized by surface chemical analysis using X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS)spectroscopy. KW - Biosensors KW - H-terminated Si3N4 films KW - Click chemistry KW - X-ray photoelectron spectroscopy KW - Near edge X-ray absorption fine structure KW - Streptavidin binding PY - 2019 U6 - https://doi.org/10.1016/j.apsusc.2019.03.002 SN - 0169-4332 VL - 481 SP - 10 EP - 15 PB - Elsevier B.V. AN - OPUS4-48634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -