Preperation of poly(ferulic acid) glassy carbon modified electrode and its electrocatalytic oxidation of NADH

The preparation of poly (ferulic acid) glassy carbon modified electrode and its electrochemical properties were studied. The modified electrode gives a quasi-reversible redox peaks in 0. 1 mol/L phosphate buffer solution(pH=6.60) over the potential range from -0. 1 to 0. 5 V(vs. Ag/AgCD, in which the formal potential is 0. 188 V(vs. Ag/AgCl). The formal potential shifts in a negative direction with the increasing of pH values. The electrode reaction contains one electron and one proton. The PFA modified electrode shows an electrocatalytic activity for the oxidation of NADH in 0. 1 mol/L phosphate buffer solution. The apparent electron transfer rate constant (k(8)). and transfer coefficient for electron transfer between the electrode surface and immobilized PFA were calculated as 6. 6 s(-1) and 0. 496, respectively, the diffusion coefficient of NADH was calculated as 1. 76 x 10(-6) cm(2)/s by using chronoamperometric results. The peak currents were proportional to the concentrations of NADH in the range of 0. 01-5. 0 mmol/L. Finally the heterogeneous rate constant for the oxidation of NADH on the PFA modified electrode surface was also determined and found to be about 6. 82 x 10(3) mol(-1) . L . s(-1).