CHITOSAN METAL OXIDES BASED NANOCOMPOSITES FOR BIOSENSING APPLICATION

Abstract

Detection of xanthine is an important biomarker as a sign of spoilage. In this work efforts have been made to fabricate a xanthine biosensor based on chitosan (CH) metal oxides (ZnO, TiO2 and MnO2), nanocomposite. The nanocomposites CH-ZnO, CHTiO2, CH-MnO2 were deposited on indium tin oxide (ITO) coated glass substrate by electrophoretic deposition process and xanthine oxidase enzyme (XOx) was immobilized on them using glutaraldehyde as crosslinking agent. Out of these three electrodes, CHTiO2/ITO electrode was chosen for further studies due to its superior electrochemical properties compared to CH-ZnO/ITO and CH-MnO2/ITO electrode. The electrochemical response of the XOx/CH-TiO2/ITO bioelectrode show high sensitivity 0.577 μA/mM or 1.15 μA/mMcm2, short response time 60 s, linear response in the xanthine concentration range from 10µM – 250µM with a detection limit of 10 µM. Further, the fabricated biosensor has been utilized to confirm xanthine in a fresh Catla (Labeo catla) fish meat sample and proved to be a simple, reliable and economical method to evaluate freshness of fish.