ELECTROCATALYSIS OF NADH OXIDATION WITH ELECTROPOLYMERIZED FILMS OF 3,4-DIHYDROXYBENZALDEHYDE

The oxidation of 3,4-dihydroxybenzaldehyde (3,4-DHB) on glassy carbon electrodes gives rise to stable redox-active electropolymerized films containing a quinone moiety. The redox response of the films is that anticipated for a surface-immobilized redox couple, and the pH dependence of the redox activity of these films is 60 mV/pH unit, which is very close to the anticipated Nernstian dependence of 59 mV/pH unit. We have characterized the dependence of the growth of these films on the solution concentration of 3,4-DHB, the potential for deposition, the time of deposition, and the pH. In addition, we have measured their permeability and apparent diffusion coefficient (D-app) of these films. These films exhibit potent and persistent electrocatalytic behavior toward NADH oxidation. In a now injection analysis determination, the limit of detection is estimated to be in the submicromolar regime.