Direct Electron Transfer and Electrocatalysis of Hemoglobin on ITO Nanoparticle Electrodes

摘要

A novel biofuel cell cathode has been developed based on direct electron transfer (DET) by using hemoglobin (Hb) as an electrocatalyst for hydrogen peroxide (H_2O_2) reduction and indium tin oxide (ITO) nanoparticles as an electrode material. The nanoparticles were prepared on an ITO-coated glass plate by liquid phase co-precipitation method, and the electrochemical characteristics were examined in phosphate buffered saline (PBS) solution (pH 7.4) containing Hb. In half-cell measurements, a large reduction current of H_2O_2 due to the electrocatalytic activity of Hb flowed and reached 130 μA cm~(-2) at -0.45 V vs. Ag|AgCl|KCl(satd.). A single cell with the H_2O_2|Hb|ITO nanoparticle cathode showed an open circuit voltage of ca. 0.75 V and a maximum power density of ca. 23 μW cm~(-2).