1985 Volume 1 Issue 3 Pages 271-274
Electrochemical investigations of 1 -MeO-PMS(1-methoxy-5-methylphenazinium methyl sulfate) and PMS (N-methylphenazinium methyl sulfate) were performed. Both 1-MeO-PMS and PMS were very strongly adsorbed only onto the basal plane of the highly oriented pyrolytic graphite and showed a reversible voltammetric response. The amounts of the adsorbed 1-MeO-PMS and PMS on the basal plane were (2.4-3.5)×10-10mol/cm2 and (3.7-6.7)×10-10mol/cm2, respectively. NADH (nicotinamide adenine dinucleotide) is oxidized by electrodes with adsorbed 1-MeO-PMS or PMS, at-0.04V. vs. Ag/AgCl at pH 7.0. The oxidation currents are proportional to the concentration of NADH. Both 1-MeO-PMS and PMS are unstable in bulk solution at pH values above 6, but are stabilized markedly by the adsorption onto the basal plane of the graphite electrodes.
