A high-performance non-enzymatic glucose sensor based on an amorphous Ga₂S₃/crystalline CuS heterojunction via facile...

Electrochemical sensors have attracted considerable interest for glucose detection due to their high sensitivity, excellent selectivity, fast response, and low cost. In this work, an amorphous Ga₂S₃/crystalline CuS heterojunction-modified ITO electrode was successfully fabricated via a simple one-step electrochemical co-deposition method with Cu doping. Operating at an optimal working potential of 0.75 V (vs. SCE), the electrode exhibited superior glucose sensing performance over a concentration range of 0.002-2 mM. Notably, the response current at 1 mM glucose was 138 times higher than that of a pure Ga₂S₃ electrode. The sensor also showed excellent selectivity against common interferents (e.g., KCl, urea, ascorbic acid) and good reproducibility (relative standard deviation = 6.28%). The enhanced sensing performance is attributed to the synergistic effect of the amorphous/crystalline heterojunction: amorphous Ga₂S₃ provides abundant defect states as active sites, crystalline CuS offers efficient electron transport channels, and the heterojunction interface promotes effective charge separation. This study presents a promising strategy for designing high-performance non-enzymatic glucose sensors.