Electrocatalytic oxidation of dihydronicotinamide adenine dinucleotide at caffeic acid glassy carbon modified electrodes

The preparation and electrochemical properties of caffeic acid modified glassy carbon electrode and the electrochemical properties have been studied. The modified electrode gives a relative reversible redox peaks in 0.1 mol/L phosphate buffer solution (pH 7.0) over the potential range from 0.0 to 0.5 V (vs. Ag/AgCl), which the formal potential is 0.250 V (vs. Ag/AgCl). The formal potential shifts negatively as pH values increased over the range of 5.0 to 8.0. The linear regression equation is E-0'=0.6233-0.05996 pH, R=0.9969, The apparent electron transfer rate constant (K-s) was 12. 3 s(-1), The electrode reaction contain two electrons and two protons process. The caffeic acid modified electrode shows electrocatalytic activity for oxidation of dihydronicotinamide adenine dinucleotide in 0.1 mol/L pH 7.0 PBS. The peak currents were proportional to the concentrations of the dihydronicotinamide adenine dinucleotide in the range of 0.1similar to6.0 mmol/L. The mechanism of electrode reaction has been discussed in this paper.