Introduction of oxygen-containing functional groups onto diamond electrodesurfaces by oxygen plasma and anodic polarization

Two simple methods for chemically modifying boron-doped diamond (BDD) films by oxidative treatment were examined. These treatments have shown promise in imparting selectivity to BDD electrodes, for example, between dopamine a nd ascorbic acid (AA). BDD surfaces were treated either by oxygen plasma or anodic polarization in alkaline solution. The treatments resulted in the i ncorporation of substantial amounts of oxygen on the surface and also incre ased the overpotential for AA oxidation. Interestingly, using cathodic pola rization, the increase in overpotential was largely negated for the anodica lly treated surface, whereas it was little affected on the plasma-treated s urface. Two different models are proposed to explain this difference in beh avior. (C) 1999 The Electrochemical Society. S1099-0062(99)05-079-6. All ri ghts reserved.