Hemoglobin co-immobilized with silver-silver oxide nanoparticles on a bare silver electrode for hydrogen peroxide electroanalysis

Hemoglobin (Hb) and silver-silver oxide (Ag-Ag2O) nanoparticles were co-immobilized on a bare silver electrode surface by cyclic voltammetry, and were characterized by UV-vis reflection spectroscopy, scanning electron microscopy, and electrochemical impedance spectroscopy. The immobilized Hb was shown to maintain its biological activity well. Direct electron transfer between Hb and the resulting electrode was achieved without the aid of any electron mediator. The reduction currents to hydrogen peroxide (H2O2) at co-immobilized electrodes showed a linear relationship with H2O2 concentration over a concentration range from 6.0 x 10(-6) to 5.0 x 10(-2) mol L-1, and a detection limit of 2.0 x 10(-6) mol L-1 (S/N = 3).