This paper reports on the formation of semicarbazide boron-doped diamond surfaces and their use for the prepn. of peptide microarrays through site-specific a-oxo semicarbazone ligation. Hydrogen-terminated diamond substrates were first photochem. oxidized and the resulting surface hydroxyl groups were coupled with (aminopropyl)triethoxysilane to yield amine-terminated surfaces. Chem. reaction of the terminal amino groups with triphosgene and Fmoc-protected hydrazine, followed by a deprotection step led to the formation of a semicarbazide termination. Peptides bearing a glyoxylyl group were linked to the semicarbazide-terminated BDD surfaces through site-specific ligation. XPS and fluorescence measurements were used to characterize the resulting surfaces.