THE EFFECT OF IRON OXIDE NANOPARTICLES CONCENTRATION ON THE ELECTROCATALYTIC PERFORMANCE OF ENZYMATIC GLUCOSE BIOSENSOR

Abstract

In this study, the enzymatic glucose biosensor was developed by modifying indium tin oxide (ITO) glass electrode with iron oxide nanoparticles (IONPs), glucose oxidase (GOx) enzyme and nafion. IONPs were synthesized using a precipitation technique and surface functionalized using citric acid (CA). The effect of iron oxide nanoparticles (IONPs) concentration (1mg/ml to 4 mg/ml) and nafion to the electrochemical performance of the modified electrode for glucose biosensor detection was studied. Increasing the concentration of IONPs increases the electrochemical performance of the bioelectrode. From the transmission electron microscopy (TEM) images, the size of IONPs obtained was ~19 nm and the X-ray diffraction (XRD) spectra showed the presence of spinel cubic lattice of maghemite (γ-Fe₂O₃). The bioelectrode designated as Nafion/Gox/IONPs-CA/ITO shows good electrochemical performance for glucose detection with high sensitivity of 90.44 µAmM^-1cm^-2 for a linear range of 1.0-12.0 mM glucose concentration.