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 a nticipated for a surface-immobilized redox couple, and the pH dependen ce of the redox activity of these films is 60 mV/pH unit, which is ver y close to the anticipated Nernstian dependence of 59 mV/pH unit. We h ave characterized the dependence of the growth of these films on the s olution concentration of 3,4-DHB, the potential for deposition, the ti me of deposition, and the pH. In addition, we have measured their perm eability and apparent diffusion coefficient (D-app) of these films. Th ese films exhibit potent and persistent electrocatalytic behavior towa rd NADH oxidation. In a now injection analysis determination, the limi t of detection is estimated to be in the submicromolar regime.