| Abstract
| - A versatile chemistry utilizing the homobifunctional cross-linker 1,4-phenylene diisothiocyanate (PDC)to attach both amine- and thiol-terminated oligonucleotides to aminosilane-coated slides was examinedin a microarray format. Three common aminosilanes, 3-aminopropyltriethoxysilane (APS), N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and m,p-(aminoethyl-aminomethyl) phenethyltrimethoxysilane, werecoated onto glass slides and silicon wafers and characterized using contact angle goniometry, ellipsometry,and X-ray photoelectron spectroscopy. Evaluation of the aminosilane-modified surfaces using contact anglemeasurements, UV−vis spectroscopy, and covalent attachment of a Cy5-conjugated N-hydroxysuccinimideester reporter molecule suggested that derivatization of the surface with APS + PDC resulted in the bestoverall coverage. Microarrays printed using APS + PDC chemistry to immobilize both amine- and thiol-terminated oligonucleotides resulted in rapid attachment, uniform spot morphology, and minimal backgroundfluorescence. Both amine- and thiol-terminated oligonucleotides showed comparable attachment, althoughgreater attachment and hybridization efficiencies were observed with amine-functionalized molecules atsaturating printing densities. The data highlight the influence of surface chemistry on both immobilizationand hybridization and, by extrapolation, on microarray data analysis.
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