Disposable biosensor based on immobilization of glucose oxidase at gold nanoparticles electrodeposited on indium tin oxide electrode

A disposable amperometric glucose biosensor based on immobilization of glucose oxidase (GOD) at the gold nanoparticles (AuNPs) electrodeposited on indium tin oxide (ITO) electrode surface has been fabricated. The AuNPs provide a good biocompatible environment for enzyme and has good promotion effects on the direct electron transfer between GOD and the electrode surface. The biosensor exhibited excellent performances for the reduction Of glucose and can respond to the change of concentration of glucose rapidly. The heterogeneous electron transfer rate constant was evaluated to be 3.7 s(-1). The amperometric response to glucose shows a linear relation in the range from 0.04 to 4.8 mmol L-1 and a detection limit of 0.015 mmol L-1 (S/N = 3). The K-M(app) value of GOD immobilized on the electrode surface was found to be 12.1 mmol L-1. The glucose biosensor indicates excellent reproducibility, good operational stability and high selectivity. The proposed method provides a new alternative to develop disposable biosensors by using gold nanoparticles electrodeposited on ITO electrode surface. (c) 2008 Elsevier B.V. All rights reserved.