Abstract
Iron oxide (Fe
3O
4) nanoparticles prepared using co-precipitation method have been dispersed in chitosan (CH) solution to fabricate nanocomposite film on indium–tin oxide (ITO) glass plate. Glucose oxidase (GOx) has been immobilized onto this CH–Fe
3O
4 nanocomposite film via physical adsorption. The size of the Fe
3O
4 nanoparticles estimated using X-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) has been found to be ∼22
nm. The CH–Fe
3O
4 nanocomposite film and GOx/CH–Fe
3O
4/ITO bioelectrode have been characterized using UV–visible and Fourier transform infrared (FTIR) spectroscopic and scanning electron microscopy (SEM) techniques, respectively. This GOx/CH–Fe
3O
4/ITO nanocomposite bioelectrode has response time of 5
s, linearity as 10–400
mg
dL
−1 of glucose, sensitivity as 9.3
μA/(mg
dL
cm
2) and shelf life of about 8 weeks under refrigerated conditions. The value of Michaelis–Menten (
K
m) constant obtained as 0.141
mM indicates high affinity of immobilized GOx towards the substrate (glucose).