title: Controlling surface functionality through generation of thiol groups in a self-assembled monolayer.
abstract: A lithographic method to generate reactive thiol groups on functionalized synthetic diamond for biosensor and molecular electronic applications is developed. We demonstrate that ultrananocrystalline diamond (UNCD) thin films covalently functionalized with surface-generated thiol groups allow controlled thiol-disulfide exchange surface hybridization processes. The generation of the thiol functional head groups was obtained by irradiating phenylsulfonic acid (PSA) monolayers on UNCD surfaces. The conversion of the functional headgroup of the self-assembled monolayer was verified by using X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS), and fluorescence microscopy. Our findings indicate the selective generation of reactive thiol surface groups. Furthermore, we demonstrate the grafting of yeast cytochrome c to the thiol-modified diamond surface and the electron transfer between protein and electrode.
authors.affiliation: Walter Schottky Institut, Technische Universität München, 85747 Garching, Germany.
authors.forename: Simon Q
authors.initials: SQ
authors.lastname: Lud
authors.forename: Stefan
authors.initials: S
authors.lastname: Neppl
authors.forename: Gerhard
authors.initials: G
authors.lastname: Richter
authors.forename: Paola
authors.initials: P
authors.lastname: Bruno
authors.forename: Dieter M
authors.initials: DM
authors.lastname: Gruen
authors.forename: Rainer
authors.initials: R
authors.lastname: Jordan
authors.forename: Peter
authors.initials: P
authors.lastname: Feulner
authors.forename: Martin
authors.initials: M
authors.lastname: Stutzmann
authors.forename: Jose A
authors.initials: JA
authors.lastname: Garrido