Abstract: A novel hydrogen peroxide biosensor based on three-dimensionally ordered macroporous graphene-doped titanium dioxide modified ITO electrode(3DOM GR-Au-TiO2/ITO) was prepared by a sol-gel procedure using polystyrene colloidal crystals as template. Catalase has been successfully immobilized on the modified electrode. The cyclic voltammetry(CV), electrochemical impedance spectra(EIS) and chronoamperometric characterizations reveal that the modified electrode exhibits an excellent electrocatalytic activity, a wide linear range for H2O2 concentration from 3.0×10-6 mol/L to 3.6×10-3 mol/L with a detection limit of 4.2×10-7 mol/L(S/N=3), fast response, high sensitivity, good reproducibility and stability.

Key words: catalase, graphene, nanometer titanium dioxide, biosensor, electrocatalysis