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.