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

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
.