ELECTROCHEMICAL CHARACTERIZATION OF NON-ENZYMATIC GLUCOSE BIOSENSOR BASED ON SILVER NANOPARTICLE (AgNPs) STABILIZED WITH SODIUM TRIPOLYPHOSPHATE (NaTPP) CROSS-LINKED CHITOSAN.

Abstract

The development of non-enzymatic glucose biosensor has garnered significant attention the recent research. This interest arises primarily from the limitations associated with enzyme-based sensors, which, despite their remarkable sensitivity and selectivity, face challenges such as inadequate stability, complex enzyme immobilization process, and stringent operational conditions including optimal temperature, and issues with reproducibility. This study presents a cost-effective and biocompatible non-enzymatic glucose biosensor utilizing silver nanoparticles (AgNPs) stabilized with sodium tripolyphosphate (NaTTP) cross-linked chitosan. The AgNPs were synthesized and characterized using Fourier transform infrared spectroscopy (FTIR), X-ray Diffractometry (XRD), and Scanning electron Microscopy (SEM). XRD analysis revealed the crystalline size of the AgNPs, while the SEM images indicated a spherical morphology with a non-uniform granular structure, which can be attributed to the bio mediated ionic gelation process. The FTIR spectrum displayed peaks between 1054-1645 cm-1, indicating the formation of phosphonate bond between the –NH3+ groups of chitosan and the –PO32- moieties of NaTTP during cross-linking process. The direct electron transfer and electro-catalytic properties of the AgNPs modified glassy carbon electrode (AgNPGCE) were examined through Potentiometric methods. The electro-catlytic oxidation of glucose at the AgNPGCE surface, along with the underlying mechanism of glucose oxidation, was elucidated through cyclic voltammetry. The AgNPGCE demonstrated superior electrochemical performance in response to glucose, exhibiting high sensitivity at +0.54 V.