Abstract: This study presents the development of a highly stable and sensitive glucose biosensor based on glucose oxidase (GOx) immobilized with chitosan (CS) on electrochemically deposited platinum nanoparticles (PtNPs). The biosensor was fabricated by electrodepositing PtNPs onto a glassy carbon electrode (GCE), followed by immobilization of GOx using CS as a biocompatible matrix. Incorporating PtNPs significantly enhanced the electrochemical activity and electron transfer kinetics, resulting in improved sensitivity, while CS improved the biosensor''s stability over time. The biosensor demonstrated a wide linear detection range of 1–13 mM glucose, with a detection limit of 0.176 mM. The biosensor exhibited high sensitivity of 23.48 μA mM?1 cm?2 and demonstrated good reproducibility and long-term stability. These results highlight the roles of CS and PtNPs in enhancing biosensor performance, indicating promising potential for practical glucose monitoring applications in clinical diagnostics.

Keywords: platinum nanoparticles, glucose, chitosan, glucose oxidase, biosensor, non-invasive