Sol-Gel Derived Cobalt-Doped CeO2 Nanocomposite on Gold Electrode for Glucose Electrochemical Sensing

Abstract

Development of a highly sensitive, repeatable glucose biosensor based on Co-doped CeO₂ nanoparticles is presented in this study. The sol-gel citrate approach was used to synthesize cobalt doped CeO₂ (Co_xCe_1-xO₂) nanoparticles (5, 10 and 15%). The X-ray diffraction (XRD), UV-visible spectroscopy, FTIR, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were applied to characterize the structure and morphology of the nanocrystal. The Co-doped CeO₂ nanoparticles-chitosan (CS) composite film was coated on an gold plate using a spin coating process. An adsorption approach created a GOX/CHIT/CCO/Au bioelectrode by immobilizing the enzyme glucose oxidase. The cyclic voltammetry and electrochemical impedance spectroscopy were used to check the electrochemical performance of biosensors. The designed biosensor had an outstanding linear response to glucose oxidase (30–220 mM) by a detection limit of 30 mM. The biosensor has an enormous affinity (K_m = 3.010 mM), excellent repeatability and storage stability up to 28 days.