Electrocatalytic Surface for the Oxidation of NADH and Other Anionic Molecules of Biological Significance

A simple electrochemical treatment of a carbon fiber electrode surface has been found to dramatically improve the voltammetry of NADH and several other anionic molecules under steady-state and fast scan (100 V/s) conditions. The electrocatalytic surface is generated through the electrochemical oxidation of NADH on a carbon fiber electrode that exhibits product adsorption. The oxidative product is reacted with ascorbic acid at elevated temperatures to create a surface which has very little overpotential for the oxidation of dopamine and many metabolites such as NADH, DOPAC, uric acid, and ascorbate. The electrochemical properties of the modified surface were examined voltammetrically at both slow and fast scan rates. The surface shown in this paper shifts the oxidation overpotentials different magnitudes for each analyte tested, thus allowing discrimination between analytes of interest and their major interferences. Another benefit of this new electrocatalytic wave is that it decreases the limit of detection for NADH by approximately 1 order of magnitude. Therefore, this new carbon surface not only gives better discrimination between two analytes but also gives better detection limits for certain analytes of interest.