The effect of electrochemical pretreatment on the catalytic activity of carbon-supported gold nanoparticles for NADH oxidation

The electrochemical oxidation of nicotinamide adenine dinucleotide (NADH) is studied systematically on four types of electrodes, i.e., glassy carbon (GC), carbon (C), Au nanoparticles (AuNP), and C-supported AuNP (AuNP/C) in a 0.05 M phosphate buffer solution (pH 7.4) before and after the electrochemical pretreatment carried out by repetitive potential scanning between −0.2 V and 1.0 V (vs. SCE) for 100 cycles. This simple pretreatment improves the electrocatalytic activity of the AuNP/C toward the NADH oxidation remarkably, suggesting the key role of Au oxide layers in facilitating the NADH electrochemical oxidation.