A review on metal and metal oxide electrodes for non-enzymatic glucose sensing applications

Diabetes mellitus is a chronic metabolic disorder that requires accurate and continuous monitoring of blood glucose levels for effective disease management. Conventional enzymatic glucose sensors suffer from limitations such as poor long-term stability, high fabrication cost, and sensitivity to environmental conditions. In contrast, non-enzymatic glucose sensors (NEGS) have attracted considerable attention because of their superior stability, rapid response, and enhanced electrocatalytic performance for direct glucose oxidation. Among various sensing materials, metal and metal oxide electrodes have emerged as promising candidates due to their excellent catalytic activity, high electrical conductivity, and large active surface area. This review comparatively analyzes different metal and metal oxide electrodes including Pt, Au, NiO, CuO, Co 3 O 4 , ZnO, Fe 2 O 3 , and MnO 2 for non-enzymatic glucose sensing applications. The electrochemical performance of these electrode materials is comparatively evaluated based on sensitivity, detection limit, selectivity, operating potential, anti-interference capability, stability, scalability, and suitability for wearable glucose monitoring systems. The review also compares the advantages and limitations of different electrode materials and identifies promising candidates for future non-enzymatic glucose sensing technologies.