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Silicon and titanium oxide surfaces (SiO₂/Si and TiO₂/Ti) were covalently modified with bioactive molecules (e.g., peptides) in a simple three-step procedure. Bioactive surfaces were synthesized by first immobilizing N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane (EDS) to either polished quartz disks, polished silicon wafers, or sputter-deposited titanium films. Subsequently, a maleimide-activated surface amenable to tethering molecules with a free thiol (e.g., cysteine) was created by coupling sulfosuccinimidyl 4-(N-maleimidomethyl) cyclohexane-1-carboxylate (sulfo-SMCC) to the terminal amine on EDS. In particular, Cys-Gly-Gly-Asn-Gly-Glu-Pro-Arg-Gly-Asp-Thr-Tyr-Arg-Ala-Tyr (-RGD-) and Cys-Gly-Gly-Phe-His-Arg-Arg-Ile-Lys-Ala (-FHRRIKA-) peptides with terminal cysteine residues were immobilized on maleimide-activated oxides. X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry were …