A sensitive nonenzymatic glucose sensor in alkaline media with a copper nanocluster/multiwall carbon nanotube-modified glassy carbon electrode

Abstract

Copper (Cu) nanoclusters were electrochemically deposited on the film of a Nafion-solubilized multiwall carbon nanotube (CNTs)-modified glassy carbon electrode (CNTs–GCE), which fabricated a Cu–CNTs composite sensor (Cu–CNTs–GCE) to detect glucose with nonenzyme. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used for the characterization of the distribution of the Cu nanoclusters on the CNTs matrix. The composite of the Cu–CNTs was investigated by the electrochemical characterization of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The preliminary study shows that the nonenzymatic sensor has synergistic electrocatalytic activity to the oxidation of glucose in alkaline media. A well applicable sensor was constructed to use for the analysis of the glucose in real blood serum samples due to the large number of electrons taking part in the oxidation process, the high apparent kinetic rate constant, and the stable operation of the electrode. The linear range for the detection of the glucose is 7.0 × 10 −7 to 3.5 × 10 −3 M with a high sensitivity of 17.76 μA mM −1, a low detection limit of 2.1 × 10 −7 M, and a fast response time of within 5 s. Experiment results also showed that the sensor has good reproducibility and long-term stability and is interference free.