Analytical Sciences

Abstract − Analytical Sciences, 17(2), 273 (2001).

Incorporation of Horseradish Peroxidase in a Kieselguhr Membrane and the Application to a Mediator-free Hydrogen Peroxide Sensor
Chunhai FAN,* Haiyan WANG,* Dexu ZHU,* Gerhard WAGNER,**  and Genxi LI* 
*Department of Biochemistry and National Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, P. R. China
**Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
Horseradish peroxidase was incorporated in a kieselguhr membrane. The electron-transfer process of the enzyme was examined by cyclic voltammetry. It was observed that the electron-transfer reactivity of horseradish peroxidase was greatly enhanced, and that direct electrochemistry was accordingly feasible. Using the merits of the direct electron-transfer reactivity of horseradish peroxidase and its specific enzymatic catalysis towards hydrogen peroxide, an unmediated hydrogen peroxide biosensor was constructed. The calibration plot of this hydrogen peroxide sensor was linear in the range of 2.0x10-6 mol/L - 6.5x10-4 mol/L. The relative standard deviation was 4.1% for 6 successive determinations at a concentration of 1.0x10-4 mol/L. The detection limit was 1.0x10-6 mol/L.