title: Application of XPS and ToF-SIMS for surface chemical analysis of DNA microarrays and their substrates.
abstract: 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.
authors.affiliation: Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 44-46, 12203, Berlin, Germany.
authors.forename: Nora
authors.initials: N
authors.lastname: Graf
authors.forename: Thomas
authors.initials: T
authors.lastname: Gross
authors.forename: Thomas
authors.initials: T
authors.lastname: Wirth
authors.forename: Wilfried
authors.initials: W
authors.lastname: Weigel
authors.forename: Wolfgang E S
authors.initials: WE
authors.lastname: Unger
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000592:standards; D012821:Silanes / Q000737:chemistry; D018629:Spectrometry, Mass, Secondary Ion; D013053:Spectrophotometry; D013499:Surface Properties; D013997:Time Factors; D014965:X-Rays
chemical_list: D004269:DNA, Bacterial; D012821:Silanes