Enzyme-free sensing of glucose on a copper electrode modified with nickel nanoparticles and multiwalled carbon nanotubes

We describe a new electrochemical platform for direct sensing of glucose. The electrode was prepared by controlled electrodeposition of nickel nanoparticles onto carbon nanotubes on a copper electrode. The sensor was optimized by investigating the effects of the concentration of nickel precursor, electrolysis time and acidity of the medium. The nanocomposite was characterized by scanning electron microscopy and energy dispersive spectroscopy. Cyclic voltammetry of glucose in 0.1 M NaOH solution gives a well-defined anodic wave with a peak potential at 0.53 V (vs. Ag/AgCl) that indicates the direct electrooxidation of glucose at the nanomaterial. The electrode responds to glucose over a wide linear range (from 2 mu M to 10 mM), with high sensitivity (3.8 mAa (TM) mM(-1)a (TM) cm(-2)) and a low detection limit (0.7 mu M). The sensor was applied to the determination of glucose in blood samples, and the results were in good agreement with data obtained by a commercially available glucometer. The method holds promise due to the ease of sensor fabrication and its robust performance and longevity.