Oxidation of beta-nicotinamide adenine dinucleotide (NADH) at poly(aniline)-coated electrodes

Poly(aniline)-poly(vinylsulfonate) composite-coated glassy carbon electrodes are found to give stable and reproducible electrocatlytic responses to NAD(P)H in citrate-phosphate buffer at pH 7. Analysis of these amperometric responses as a function of NAD(P)H concentration, film thickness, electrode potential and rotation speed show that the reaction occurs within the film, rather than just at the outside, and that the reaction is reversibly inhibited by the oxidation product [NA(P)D+]. Based on a full kinetic analysis, rate constants for the various processes are determined.