The Self-Adsorption of Ni Ultrathin Layer on Glassy Carbon Surface and Their Electrocatalysis toward Glucose

The Ni ultrathin layer was obtained by the simple self-adsorption of Ni2+ on the surface of glassy carbon electrode. Through a consecutive potential scan in alkali solution, the adsorbed Ni2+ was transformed to the ultrathin layer of Ni(OH)(2)/NiOOH which exhibits good electrocatalysis toward the oxidation of glucose. Only a little of Ni2+ was consumed to obtain such an ultrathin layer of Ni with excellent electrochemical performance. Due to the low diffusion hindrance and the good electrocatalytic property of Ni(OH)(2)/NiOOH ultrathin structure, the electrode response toward glucose reaches a steady-state level within only 4 s, demonstrating a rapid and sensitive response. The calibration plot is linear over the wide concentration range of 0 similar to 7 mM with a slope of 1.01 mu A/mM (sensitivity) and a correlation coefficient of 0.9996. The detection limit of the electrode was found to be 10.9 mu M at a signal-to-noise ratio of 3. The adsorption method is very simple and the ultrathin layer of Ni was formed in a controllable manner with the size lower than nanoscale, which will find the potential applications in nanofabrication for the nanodevices of fuel cell or electrochemical sensor in the future. (C) 2014 The Electrochemical Society. All rights reserved.