ELECTROCHEMICAL PEROXIDASE SENSOR BASED ON MAGNESIUM OXIDE-CHITOSAN NANOBIOCOMPOSITE FILM

Abstract

Nanoparticles play a major role in development of new hybrid composites for various engineering applications. A simple and novel amperometric biosensor for hydrogen peroxide detection is proposed. It is based on the immobilization of Horseradish peroxidase (HRP) in a chitosan (CH) matrix directly on a gold electrode surface (HRP/CH-NanoMgO/Au). Hydrogen peroxide was determined by direct electron transfer between the electrode surface and HRP. The MgO nanoparticles are prepared with sol-gel method. Synthesized nanoparticle was characterized by X-ray diffraction. XRD shows the average particle size was found to be ~ 16 nm for MgO. CH-NanoMgO/Au electrode and HRP/CH-NanoMgO/Au bioelectrode has been characterized by the scanning electron microscopy (SEM), Cyclic voltammetry (CV) demonstrated the fast electron transfer process between HRP and the electrode. The resulted H₂O₂ biosensor exhibited a rapid response upon the addition of H₂O₂, a low detection limit of 37.64 µM. The linear range of the biosensor is from 50-350 µM (R²=0.97). A novel horseradish peroxidase (HRP) electrochemical biosensor based on a CH-NanoMgO/Au composite matrix was developed with easy preparation and low cost can provide a matrix for enzyme immobilization to construct biosensors with higher performance.

Keywords: Biosensor, MgO nanoparticles, Horseradish peroxidase (HRP), Chitosan (CH), Sol gel method.