TY - JOUR A1 - Graf, Nora A1 - Gross, Thomas A1 - Wirth, Thomas A1 - Weigel, W. A1 - Unger, Wolfgang T1 - Application of XPS and ToF-SIMS for surface chemical analysis of DNA microarrays and their substrates JF - Analytical and bioanalytical chemistry N2 - The chemical composition of the functional surfaces of substrates used for microarrays is one of the important parameters that determine the quality of a microarray experiment. In addition to the commonly used contact angle measurements to determine the wettability of functionalized supports, X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) are more specific methods to elucidate details about the chemical surface constitution. XPS yields information about the atomic composition of the surface, whereas from ToF-SIMS, information on the molecular species on the surface can be concluded. Applied on printed DNA microarrays, both techniques provide impressive chemical images down to the micrometer scale and can be utilized for label-free spot detection and characterization. Detailed information about the chemical constitution of single spots of microarrays can be obtained by high-resolution XPS imaging. KW - Microarrays KW - Surface analysis KW - XPS KW - ToF-SIMS KW - Chemical imaging PY - 2009 DO - https://doi.org/10.1007/s00216-009-2599-x SN - 1618-2642 SN - 1618-2650 VL - 393 IS - 8 SP - 1907 EP - 1912 PB - Springer CY - Berlin AN - OPUS4-19245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Graf, Nora A1 - Yegen, E. A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Weigel, W. A1 - Krakert, S. A1 - Terfort, A. A1 - Unger, Wolfgang T1 - XPS and NEXAFS studies of aliphatic and aromatic amine species on functionalized surfaces JF - Surface science N2 - The chemical constitution of functionalized supports is an important parameter that determines their performance in a broad range of applications, e.g. for immobilization of biomolecules. Supports with amino functionalized surfaces are also often used for DNA microarray experiments. However, spectral data which have been reported for surfaces with amino functionalities suffer from some inconsistencies. In this article a detailed XPS (X-ray photoelectron spectroscopy) and NEXAFS (Near edge X-ray absorption fine structure) database for amino functionalized surfaces is presented. Amino-terminated surfaces prepared from aliphatic and aromatic aminosilanes or aminothiols and a field sample are considered. Effects of aging in air and damage by radiation are addressed as well. KW - Near edge X-ray absorption fine structure (NEXAFS) KW - Self-assembled monolayers KW - Amino-functionalized surfaces KW - X-ray photoelectron spectroscopy (XPS) PY - 2009 DO - https://doi.org/10.1016/j.susc.2009.07.029 SN - 0039-6028 VL - 603 IS - 18 SP - 2849 EP - 2860 PB - Elsevier CY - Amsterdam AN - OPUS4-19832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -