Superoxide sensor based on hemin modified electrode

A hemin modified pyrolytic graphite (PG) electrode was prepared and applied for the electrochemical determination of superoxide. The rate constant of heterogeneous electron transfer of adsorbed hemin was determined with cycli c voltammetry (CV) to be 15 s(-1). The hemin modified electrode was applied to detect superoxide radicals produced by xanthine oxidase (XOD) catalyzed hypoxanthine oxidation. Sensitivity was higher than compared to the establ ished cytochrome c (cyt c)-based sensor. The antioxidative activity of supe roxide dismutase (SOD) and uric acid was also investigated. (C) 2000 Elsevi er Science B.V. All rights reserved.