Direct Electrochemical Behavior of Horseradish Peroxidase Entrapped in Agarose Hydrogel Films

Horseradish peroxidase was immobilized on glassy carbon electrode(GCE)surface by agarose hydrogel.Horseradish peroxidase entrapped in the agarose film in phosphate buffer solution and phosphate buffer ethanol mixed solvent undergoes fast direct electron-transfer reactions with the formal potential(E01)of-0.392V(vs SCE)and-0.412V(vs SCE)respectively,corresponding to Fe3++e-→Fe2+.The E01 is linearly dependent on pH of the buffer solution with the slope value of-56.0mV/pH,indicating that the electron transfer is proton-coupled.