▎ 摘　　要

The authors describe the synthesis of a nanocomposite consisting of graphene oxide, cobalt(III) oxide and horseradish peroxidase (HRP/GO-Co3O4) in a nafion matrix. The composite, when deposited on a glassy carbon electrode (GCE), is shown to enable electrochemical sensing of H2O2. The morphology of the nanocomposite was characterized by field emission scanning electron microscopy, X-ray diffraction spectroscopy, energy dispersive X-ray spectroscopy, UV-vis spectroscopy, and FTIR spectroscopy. The response of the modified electrode to H2O2 was examined by cyclic voltammetry and DC potential amperometry at a working potential -0.57 V (vs. Ag/AgCl) at pH 7.0. Features include (a) a sensitivity of -18.7 +/- 0.5 mu A mM(-1) cm(-2), (b) a linear dynamic range from 1 mM to 30 mM, (c) a 2 mM detection limit, and (d) a response time of similar to 20 s. The performance of the sensor for the routine analysis was investigated by the determination of H2O2 present in hair dye product with appreciable percent recovery value. Moreover, the HRP/GO-Co3O4-nafion/GCE biosensor exhibited good selectivity towards H2O2 quantification in presence of common interfering species such as glucose, uric acid and ascorbic acid. This good analytical performance makes this biosensor a promising tool for sensing of H2O2.