A novel strategy for realizing highly sensitive nonenzymatic detection of H2O2 based on regulating crystallinity of CoO nanosheets

This study reports a novel strategy to construct a highly sensitive electrochemical sensing method based on crystallinity regulation. Two kinds of CoO nanosheets with different crystallinity were prepared by adjusting annealing temperature. The results show that decreasing crystallinity of CoO nanosheets not only increases electrochemical surface area but also accelerates electron transport rate. This is beneficial to improve the electrocatalytic activity of CoO nanosheets for electrochemical oxidation of H2O2, and therefore makes the sensor detect H2O2 in a linear range of 0.2 mu M to 11 mM, a sensitivity of 909.9 mu A<middle dot>mM(-1)<middle dot>cm(-2) and a low detection limit of 0.2 mu M. This study provides a new perspective to regulate the electrocatalytic activity of nanomaterials for constructing highly sensitive electrochemical sensor.