Improvement of sensitive CuO NFs-ITO nonenzymatic glucose sensor based on in situ electrospun fiber

CuO nanofibers (NFs), prepared by electrospinning and calcination technologies, have been applied for the fabrication of glucose sensors with high sensitivity and selectivity. Cu(NO3)(2) and polyvinylpyrrolidone (PVP) composite nanofibers were initially electrospun on the surface of indium tin oxide (ITO) glass, and then the CuO NFs-ITO electrode was formed simply by removing PVP through heat treatment. The structures and morphologies of CuO nanofibers were characterized by X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The direct electrocatalytic oxidation of glucose in alkaline medium at CuO NFs-ITO electrode has also been investigated in detail with cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The effects of NaOH concentration, electrospinning time, Cu(NO3)(2):PVP mass ratios and calcination temperature on the response to glucose were investigated. Under optimized experimental conditions, the CuO NFs-ITO electrode produced high and reproducible sensitivity to glucose of 873 mu A mM(-1) cm(-2). Linear responses were obtained over a concentration range from 0.20 mu M to 1.3 mM with a detection limit of 40 nM (S/N= 3). The CuO NFs-ITO electrode also has good selectivity, stability and fast amperometic sensing of glucose, thus it can be used for the future development of non-enzymatic glucose sensors. (C) 2012 Elsevier B.V. All rights reserved.