A novel glucose biosensor based on immobilization of glucose oxidase in iron oxide nanoparticles/poly(vinyl alcohol) nanocomposite film

Abstract

This report describes an electrochemical biosensor for the detection of glucose. Iron oxide nanoparticles were prepared via co-precipitation method. Synthesized nanoparticles were dispersed in poly(vinyl alcohol) (PVA) solution to fabricate PVA-Fe 3 O 4 nanocomposite. Glucose oxidase (GOx) was immobilized by physical adsorption in PVA-Fe 3 O 4 nanocomposite for the construction of glucose biosensor. X-ray diffraction (XRD) pattern of synthesized Fe 3 O 4 nanoparticles illustrated reflection planes, which are exactly similar to the standard pattern for Fe 3 O 4 nanoparticles. The crystal size of Fe 3 O 4 nanoparticles calculated using Debye-Scherrer formula is obtained about 3 nm. The PVA-Fe 3 O 4 and PVA-Fe 3 O 4 /GOx nanocomposites were characterized using Fourier transform infrared (FTIR) spectroscopic and field emission scanning electron microscopy (FESEM) techniques. Results showed that Fe 3 O 4 nanoparticles were almost uniformly dispersed in the PVA matrix with minimum aggregation and GOX was successfully immobilized on the PVA-Fe 3 O 4 matrix. The electrochemical measurement was carried out by cyclic voltammetry (CV). GOx showed excellent catalytic activity to glucose. The presence of Fe 3 O 4 nanoparticles in modified electrode enhanced the electron transfer between enzyme molecule and the electrode surface. This GOx/PVA-Fe 3 O 4 /Sn bioelectrode can estimate different concentration of glucose from 30–400 mg dL−1.