A highly sensitive nonenzymatic glucose sensor based on CuO nanoparticles-modified carbon nanotube electrode

In this report, a novel type of cupric oxide (CuO) nanoparticles-modified multi-walled carbon nanotubes (MWCNTs) array electrode for sensitive nonenzymatic glucose detection has been fabricated. The morphology of the nanocomposite was characterized by transmission electron microscopy and X-ray diffraction. The electrochemical performance of the CuO/MWCNTs electrode for detection of glucose was investigated by cyclic voltammetry and chronoamperometry. The CuO/MWCNTs electrode showed much higher electrocatalytic activity and lower overvoltage than the bare MWCNTs electrode towards oxidation of glucose. At an applied potential of +0.40 V, the CuO/MWCNTs electrode presented a high sensitivity of 2596 microA mM(-1) cm(-2) to glucose. In addition, linear range was obtained over a concentration up to 1.2 mM with a detection limit of 0.2 microM (signal/noise=3). The response time is about 1s with addition of 0.10 mM glucose. More importantly, the CuO/MWCNTs electrode is also highly resistant against poisoning by chloride ion, and the interference from the oxidation of common interfering species such as ascorbic acid, dopamine, uric acid and carbohydrate compounds is effectively avoided. In addition, the CuO/MWCNTs electrode was also used to analyze glucose concentration in human serum samples. The CuO/MWCNTs electrode exhibits an enhanced electrocatalytic property, low working potential, high sensitivity, excellent selectivity, good stability, and fast amperometric sensing towards oxidation of glucose, thus is promising for the future development of nonenzymatic glucose sensors.