Hydrogen peroxide biosensor based on direct electrochemistry of hemoglobin immobilized on carbon paste electrode by a silica sol–gel film

Direct electrochemistry of hemoglobin (Hb) immobilized on carbon paste electrode (CPE) by a silica sol–gel film derived from tetraethylorthosilicate (TEOS) was investigated for the first time. Nevertheless, it still maintains its original structure after immobilization by sol–gel film. Hb/sol–gel modified electrode shows a thin layer electrochemistry behavior. The immobilized Hb displays the features of peroxidase and gives excellent performance in the electrocatalytic reduction of hydrogen peroxide (H2O2). Based which an unmediated biosensor for H2O2 was developed. H2O2 sensor exhibits a high sensitivity and a long-term stability.