TY - JOUR A1 - Dietrich, Paul A1 - Graf, Nora A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Schüpbach, B. A1 - Bashir, A. A1 - Wöll, Ch. A1 - Terfort, A. A1 - Unger, Wolfgang T1 - Self-assembled monolayers of aromatic omega-aminothiols on gold: surface chemistry and reactivity N2 - Amino-terminated self-assembled monolayers on gold substrates were studied by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS) measurements, and atomic force microscopy (AFM). Two different ω-amino-4,4'-terphenyl substituted alkanethiols of the general structure H2N-(C6H4)3-(CH2)n-SH (ATPn) were used: 2-(4''-amino-1,1':4',1''-terphenyl-4-yl)ethane-1-thiol (n = 2, ATP2) and 3-(4''-amino-1,1':4',1''-terphenyl-4-yl)propane-1-thiol (n = 3, ATP3). Moreover, the addressability of amino groups within the films was investigated by chemical derivatization of ATPn SAMs with 3,5-bis(trifluoromethyl)phenyl isothiocyanate (ITC) forming fluorinated thiourea ATPn-F films. Evaluation of high-resolution C 1s and N 1s XPS data revealed successful derivatization of at least 50% of surface amino species. Furthermore, it could be demonstrated by angle-resolved NEXAFS spectroscopy that chemical derivatization with ITC has no noticeable influence on the preferential upright orientation of the molecules in the SAMs. KW - Gold KW - Self-assembled monolayer KW - Thiols KW - Amino surfaces KW - XPS KW - NEXAFS PY - 2010 DO - https://doi.org/10.1021/la903293b SN - 0743-7463 SN - 1520-5827 VL - 26 IS - 6 SP - 3949 EP - 3954 PB - American Chemical Society CY - Washington, DC AN - OPUS4-20990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dietrich, Paul A1 - Horlacher, T. A1 - Gross, Thomas A1 - Castelli, R. A1 - Rurack, Knut A1 - Seeberger, P. H. A1 - Unger, Wolfgang T1 - Optimization of carbohydrate microarray performances T2 - Bunsentagung 2010 "Interfacial Systems Chemistry: Out of the Vacuumm, Through the Liquid, Into the Cell" CY - Bielefeld, Germany DA - 2010-05-13 PY - 2010 AN - OPUS4-21366 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul A1 - Glamsch, Stephan A1 - Ehlert, Christopher A1 - Lippitz, Andreas A1 - Kulak, N. A1 - Unger, Wolfgang T1 - Synchrotron-radiation XPS analysis of ultra-thin silane films: Specifying the organic silicon N2 - The analysis of chemical and elemental in-depth variations in ultra-thin organic layers with thicknesses below 5 nm is very challenging. Energy- and angle-resolved XPS (ER/AR-XPS) opens up the possibility for non-destructive chemical ultra-shallow depth profiling of the outermost surface layer of ultra-thin organic films due to its exceptional surface sensitivity. For common organic materials a reliable chemical in-depth analysis with a lower limit of the XPS information depth z95 of about 1 nm can be performed. As a proof-of-principle example with relevance for industrial applications the ER/AR-XPS analysis of different organic monolayers made of amino- or benzamidosilane molecules on silicon oxide surfaces is presented. It is demonstrated how to use the Si 2p core-level region to non-destructively depth-profile the organic (silane monolayer) – inorganic (SiO2/Si) interface and how to quantify Si species, ranging from elemental silicon over native silicon oxide to the silane itself. The main advantage of the applied ER/AR-XPS method is the improved specification of organic from inorganic silicon components in Si 2p core-level spectra with exceptional low uncertainties compared to conventional laboratory XPS. KW - Synchrotron radiation XPS KW - Depth profiling KW - Silanes KW - Monolayer KW - Amines KW - Amides PY - 2016 DO - https://doi.org/10.1016/j.apsusc.2015.12.052 SN - 0169-4332 SN - 1873-5584 VL - 363 SP - 406 EP - 411 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-35262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darlatt, Erik A1 - Nefedov, A. A1 - Traulsen, C.H.-H. A1 - Poppenberg, J. A1 - Richter, S. A1 - Dietrich, Paul A1 - Lippitz, Andreas A1 - Illgen, René A1 - Kühn, Julius A1 - Schalley, C.A. A1 - Wöll, Ch. A1 - Unger, Wolfgang T1 - Interperetation of experimental N K NEXAFS of azide, 1,2,3-triazole and terpyridyl groups by DFT spectrum simulations N2 - Experimental N K-edge NEXAFS data of surface immobilized azide, 1,2,3-triazole and terpyridyl groups are interpreted with the help of DFT spectrum simulations. Assignments of π* resonances in experimental N K-edge NEXAFS spectra to nitrogen atoms within these functional groups have been made. The azide was immobilized on gold as the head group of a thiol SAM, 1,2,3-triazole was formed on this SAM by click reaction and terpyridyl groups were introduced as substituents of the acetylene used for the click reaction. For azide-terminated molecules, DFT spectrum simulations are found to be useful to find measurement conditions delivering experimental N K-edge NEXAFS data with negligible X-ray damage. The 1,2,3-triazole group is found to be rather stable under X-ray irradiation. KW - N K-edge NEXAFS KW - XANES KW - Surface click chemistry KW - Density functional theory KW - Azide KW - 1,2,3-Triazole PY - 2012 DO - https://doi.org/10.1016/j.elspec.2012.09.008 SN - 0368-2048 SN - 1873-2526 VL - 185 IS - 12 SP - 621 EP - 624 PB - Elsevier CY - Amsterdam AN - OPUS4-27774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul A1 - Horlacher, T. A1 - Gross, Thomas A1 - Wirth, Thomas A1 - Castelli, R. A1 - Shard, A.G. A1 - Alexander, M. A1 - Seeberger, P.H. A1 - Unger, Wolfgang T1 - Surface analytical characterization of carbohydrate microarrays N2 - Microarrays are a versatile platform for diagnostics and high-throughput analysis. Carbohydrate microarrays are valuable tools to investigate interactions with other molecules since many glycans are involved in fundamental biological processes. A combined X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) surface analysis was used to investigate the basic steps in the production of carbohydrate microarrays. The preparation included coupling of a thiol-terminated mannoside to maleimide-functionalized glass surfaces derived from γ-aminopropyl silane (GAPS) slides. XPS results clearly demonstrate successful chemical modification in each fabrication step, and ToF-SIMS imaging revealed immobilized carbohydrates in the spotted regions of the final microarray. KW - Carbohydrates KW - Microarrays KW - XPS KW - ToF-SIMS KW - Nona-mannoside KW - Maleimide surfaces KW - Surface analysis PY - 2010 DO - https://doi.org/10.1002/sia.3255 SN - 0142-2421 SN - 1096-9918 VL - 42 SP - 1188 EP - 1192 PB - Wiley CY - Chichester AN - OPUS4-21500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul A1 - Horlacher, T. A1 - Girard-Lauriault, Pierre-Luc A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Min, Hyegeun A1 - Wirth, Thomas A1 - Castelli, R. A1 - Seeberger, P. A1 - Unger, Wolfgang T1 - Multimethod chemical characterization of carbohydrate-functionalized surfaces N2 - A combined XPS, NEXAFS, and ToF-SIMS chemical surface characterization of carbohydrate-functionalized gold and glass surfaces is presented. Spot shape and chemical composition across a spot surface are provided by surface-sensitive methods as ToF-SIMS and XPS, used in their imaging modes. Moreover, the feasibility of this multimethod approach to control relevant production steps of a carbohydrate microarray prototype is demonstrated. KW - Carbohydrates KW - Microarrays KW - Self-assembled monolayers KW - XPS KW - NEXAFS KW - ToF-SIMS PY - 2011 DO - https://doi.org/10.1080/07328303.2011.615181 SN - 0732-8303 VL - 30 IS - 4-6 SP - 361 EP - 372 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-24874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dietrich, Paul A1 - Horlacher, T. A1 - Girard-Lauriault, Pierre-Luc A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Min, Hyegeun A1 - Wirth, Thomas A1 - Castelli, R. A1 - Seeberger, P. H. A1 - Unger, Wolfgang T1 - Surface chemical characterization of carbohydrate films on gold T2 - ECASIA '11 CY - Cardiff, Wales DA - 2011-09-09 PY - 2011 AN - OPUS4-24239 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dietrich, Paul A1 - Unger, Wolfgang T1 - Entwicklung einer normativen analytischen Infrastruktur für die Qualitätssicherung von Mikroarrays T2 - 3. Berlin-Brandenburger Technologieforum In Vitro-Diagnostik und Bioanalytik CY - Potsdam, Germany DA - 2011-06-09 PY - 2011 AN - OPUS4-23965 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dietrich, Paul A1 - Funk, Christian A1 - Gross, Thomas A1 - Unger, Wolfgang A1 - Weigel, W. T1 - Epoxy-functionalized Surfaces: Surface chemical analysis and fluorescence labeling of surface species T2 - ECASIA '11 CY - Cardiff, Wales DA - 2011-09-09 PY - 2011 AN - OPUS4-24242 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dietrich, Paul A1 - Horlacher, T. A1 - Gross, Thomas A1 - Castelli, R. A1 - Wirth, Thomas A1 - Seeberger, P. H. A1 - Unger, Wolfgang T1 - Surface chemical Analysis of Microarrays: Problems and Perspectives T2 - ECASIA'11 CY - Cardiff, Wales DA - 2011-09-09 PY - 2011 AN - OPUS4-24243 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -