Nanoparticles of Ni(OH)2 embedded in chitosan membrane as electrocatalyst for non-enzymatic oxidation of glucose

We demonstrate, for the first time, the chemical/electrochemical synthesis of uniformly dispersed nickel hydroxide nanoparticles (NPs) embedded in a chitosan (CS) membrane deposited onto a glassy carbon (GC) electrode. The morphology of this composite was investigated by scanning electron microscopy (SEM). The SEM results show that NPs have nano-globular structure in the range 10-100 nm. This composite displays electrocatalytic activity toward oxidation of glucose in alkaline solution. The electrochemical properties of the resulting material deposited as a redox film have been investigated by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. Using Lavirin's theory, the electron-transfer rate constant and the transfer coefficient were determined to be k(s) = 4.1 s(-1) and alpha = 0.42, respectively, for a modifier film (Gamma(Ni) =7.1 x 10(-10) mol cm(-2)) on a GC electrode in 0.1 M sodium hydroxide solution. The modified electrode for glucose oxidation is characterized by simple preparation, good stability, good reproducibility, and data from the amperometric current time curves recorded by holding the potential of the modified electrode at 0.75V for 60 s for different glucose concentrations show a sensitivity of 72 mu A mM(-1) cm(-2). (C) 2013 Elsevier Ltd. All rights reserved.