Electrochemical and enzymic oxidation of 9-methyluric acid at solid electrodes

Abstract

The electrochemical oxidation of 9-methyluric acid has been studied in the pH range 2.0–11.3 at pyrolytic graphite, platinum and glassy carbon electrodes. The oxidation was found to occur in a single 2e^–, H⁺ pH-dependent reaction at all the three electrodes. Adsorption complications were observed at the pyrolytic graphite and glassy carbon electrodes whereas no such behaviour was observed at platinum. The UV-spectral changes and the kinetics of the decay of the UV-absorbing intermediate generated during the reaction were found to be essentially the same at all the three electrodes. The peroxidase catalysed oxidation of 9-methyluric acid was also found to be similar to the electrochemical oxidation. The products of oxidation were the same at all the electrodes suggesting thereby that adsorptive action at the surface of PGE and GCE did not affect the EC mechanism.