The investigation of novel glucose oxidase biosensor based on graphene-clay nanocomposite

Abstract

A feasible and fast method to fabricate glucose biosensor was developed by immobilisation of glucose oxidase (GOx) to nano-sepiolite-graphene nanocomposite/glassy carbon electrode. The direct electrochemistry of glucose oxidase not containing medioter and worked in air saturated condition for similarity of in vivo usage. The nano-sepiolite-graphene nanocomposite shows a high conductive and biocompatible template for enzyme immobilisation. The immobilised GOx on nanocomposite shows a couple of well defined reversible peak with the anodic and cathodic peak potentials of –430 and –460 mV (vs. Ag/AgCl), corresponding to the FAD/FADH2 redox couple, and with a formal potential of –445 mV in 0.1 M phosphate buffer solution at pH = 7. The linear concentration rang of biosensor is 0.14–3.14 µM, and with detection limit of 0.04 µM. Also, the life time of biosensor is more than four months.