Functionalization of Carbon Nanotubes with Copper for Nonenzymatic Electrochemical Detection of Glucose

The stable Cu nanoparticles decorated polydopamine coated carbon nanotubes (Cu-pDA@CNTs) have been synthesized through a mild chemical route in water assisted with an exogenous reducing agent of NaBH4. The morphology, crystallinity, and surface property of the as-prepared Cu-pDA@CNTs were examined by transmission electron microscope (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical catalytic activity of Cu-pDA@CNTs for glucose electrooxidation was also investigated by cyclic voltammetry and amperometry in details. In an alkaline solution, the amperometric current response of the modified electrode to glucose shows a linear concentration range of 0.05 mM to 10.5 mM with a correlation coefficient of 0.9963 and the calculated limit of detection is 0.27 mu M. Furthermore, this nonenzymatic glucose sensor displayed many desirable properties such as good reproducibility, long-term stability, fast current response, and low interference. Because of these attractive properties, the proposed glucose sensor has great potential in the applications of point-of-care diagnostics.