Enzyme-free amperometric sensing of hydrogen peroxide and glucose at a hierarchical Cu2O modified electrode

In this paper, an enzyme-free amperometric electrochemical sensor was fabricated by casting Nafion-impregnated Cu2O particles onto a glassy carbon electrode. A dual dependence of peak current on sweeping rate, which can be attributed for the accumulation of reaction products, was observed on the sensor. Electrochemical analysis of the particulate Cu2O for detecting H2O2 and glucose is described, showing remarkable sensitivity in both cases. The estimated detection limits and sensitivities for H2O2 (0.0039 mu M, 52.3 mA mM(-1) cm(-2)) and glucose (47.2 mu M, 0.19 mA mM(-1) cm(-2)) suggest that the response for H2O2 detection was much higher than for glucose detection. Electron microscopy observation suggested that the hierarchical structures of Cu2O resulting from self-assembly of nanocrystals are responsible for the specific electrochemical properties. (C) 2011 Elsevier B.V. All rights reserved.