Layer-by-layer assembly of copper nanoparticles and manganese dioxide-multiwalled carbon nanotubes film: A new nonenzymatic electrochemical sensor for glucose

A nonenzymatic glucose sensor based on Cu/MnO2/MWCNTs nanocomposite modified glass carbon electrode was fabricated by an electrochemical method. Transmission electron microscopic (TEM) measurement showed that MnO2 in the nanocomposite held a nanostructure of three-dimension (3D) spheres assembled by many densely arranged nanosheets. The electrocatalytic activity of the present sensor toward the oxidation of glucose was investigated by amperometry. The current response was linearly related to glucose concentration in a range from 6.4 x 10(-7)-2.0 x 10(-3) mol L-1 with a sensitivity of 494 mu A mM(-1) cm(-2) and a correlation coefficient of 0.9990, and another range from 10 to 1000 mu M with a sensitivity of 1302 mu A mM(-1) cm(-2) and a correlation coefficient of 0.9990. The detection limit was estimated to be 0.17 mu M at a signal-to-noise ratio of 3, and the response time was found to be 3 s. (C) 2015 Elsevier B.V. All rights reserved.