A hydrogen peroxide biosensor based on the bioelectrocatalysis of hemoglobin incorporated in a kieselgubr film

An unmediated hydrogen peroxide biosensor was prepared by co-immobilizing hemoglobin (Hb) with kieselgubr at a pyrolytic graphite electrode surface. Hb exhibited direct electrochemistry in the film, as well as peroxidase-like activity. This modified electrode showed high stability, catalytic activity towards the reduction of hydrogen peroxide. A linear dependence of the catalytic current on the concentration of hydrogen peroxide was observed in the concentration range of 5.0 x 10(-6) to 3.0 x 10(-4) mol/l with a detection limit of 2.1 x 10(-6) mol/l. The apparent Michaelis-Menten constant (K-M(app)) was estimated to be 975 mumol/l. (C) 2002 Elsevier Science B.V. All rights reserved.