Electrocatalysis of NADH oxidation with electropolymerized films of nile blue A

A stable electroactive thin film of poly(nile blue A) (PNB) has been deposited on the surface of a glassy carbon electrode by cyclic voltammetry in an aqueous solution containing nile blue A (NB). Cyclic voltammograms of PNB indicate the presence of two redox couples and the formal potential shifts toward negative direction with increasing solution pH. The PNB modified glassy carbon electrode shows excellent electrocatalytic activity toward NADH oxidation in phosphate buffer solution (pH 6.8), with an overpotential which is more than 660 mV lower than that of the bare electrode. The catalytic rate constant of the modified glassy carbon electrode for the oxidation of NADH is determined by cyclic voltammetry and rotating disk electrode measurements.