Ultrasensitive Enzyme‐Free Electrochemical Glucose Sensing Using Iron Oxide–Cellulose Composite Electrodes

Abstract Iron oxide (Fe 2 O 3 ), renowned for its superparamagnetic properties, ease of preparation, low cost, and large surface area has captured widespread attention in modern scientific research. The rationale behind employing cellulose as a dopant is driven by its biocompatibility, stabilizing effect, enhanced mechanical properties, facilitation of electron transfer, biodegradability, and versatility. Due to their biocompatibility, high surface area for immobilizing biomolecules, magnetic manipulation capabilities, and ease of functionalization, iron oxide‐cellulose composites stand as a good choice for biosensor applications. This study introduces a novel glucose biosensor utilizing the prepared iron oxide‐cellulose composite. The biosensor is capitalized on the distinctive attributes of iron oxide nanoparticles and cellulose, resulting in a highly effective platform for glucose detection. The active materials, coated on FTO‐based current collectors work as the working electrode. Following the fundamental characterizations, electrochemical studies are conducted using cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. The sensitivity of the sample was determined to be 0.17 µA/mM/cm 2 , while the Limit of Detection (LOD) was calculated to be 62 µM and the Limit of Quantification (LOQ) was found to be 208 µM, which held promise for practical applications in glucose monitoring.