▎ 摘　　要

A novel hydrogen peroxide biosensor was prepared by entrapping horseradish peroxidase (HRP) by electropolymerization of toluidine blue onto a graphene-toluidine blue nanocomposite-modified base electrode. Graphene and the graphene-toluidine blue nanocomposites were characterized by SEM and UV-Vis spectroscopy. The preparation of the biosensor was monitored using electrochemical impedance spectroscopy. The catalytic performances of the biosensor were investigated using cyclic voltammetry and chronoamperometry. The performance of the biosensor was evaluated, and the results indicated that the biosensor exhibited excellent catalytic performance for the detection of hydrogen peroxide. The linear response range of the biosensor for hydrogen peroxide was 5.0x10(-7)similar to 1.35x10(-5) mol.L-1 with a sensitivity of 4.32 mu A.L.mu mol(-1), a correlation coefficient of 0.999 and a detection limit of 3.5x10(-7) mol.L-1 (S/N=3).