Amperometric nonenzymatic determination of glucose via a glassy carbon electrode modified with nickel hydroxide and N-doped reduced graphene oxide

Abstract

The authors describe a nonenzymatic glucose sensor that was obtained by electrochemical deposition and oxidization of metallic nickel on the surface of nitrogen-doped reduced graphene oxide (N-RGO) placed on a glassy carbon electrode (GCE). An analysis of the morphology and chemical structure indicated the composite to possess a well-defined vermicular Ni(OH)2 nanorods combined with N-RGO. The electrochemical performance of the modified GCE with respect to the detection of glucose in 0.1 M NaOH was investigated by cyclic voltammetry and amperometry. The wrinkle and protuberance of N-RGO for loading of nanostructured Ni(OH)2 are found to increase electrical conductivity, surface area, electrocatalytical activity and stability. The modified GCE displays a high electrocatalytic activity towards the oxidation of glucose in 0.1 M NaOH solution. The lower detection limit is 0.12 μM at an applied potential of +0.45 V (vs Ag/AgCl) (S/N=3), and the sensitivity is 3214 μA mM−1 cm−2. The modified GCE possesses long-term stability, good reproducibility and high selectivity over fructose, sucrose and lactose.