Preparation and electrochemical investigation of a nano-structured material Ni2+/MgFe layered double hydroxide as a glucose biosensor

A simple and cheap biosensor was proposed based on glassy carbon electrode (GCE) modified with a nano-structured material Ni2+/MgFe layered double hydroxide (NLDH), chitosan (CHT) and glucose oxidase (GOD). The material NLDH prepared by coprecipitation and/or the fabricated biosensor GOD-NLDH-CHT-GCE was characterized by X-ray diffraction, infrared spectrum, X-ray fluorescence spectroscopy, thermogravimetric-differential thermal analysis, transmission electron microscopy, scanning electron microscopy, electrochemical impedance spectroscopy and UV-Vis spectroscopy. Optimization of experimental parameters was investigated with regard to the amount of modifier, pH and applied potential. The optimized amperometric biosensor characteristics covered 1-20 mM glucose concentration with a detection limit of 0.12 mM (S/N = 3) and a fast response (<5 s). In addition, the biosensor exhibited satisfactory reproducibility and a long-time stability, retaining 90% of its original activity after 30 days. (C) 2011 Elsevier B.V. All rights reserved.