Enzyme-Functionalized Field-Effect Transistors Based on Liquid-Metal-Derived Ultrathin SnO2 Films for Glucose Detection

• • Ultrahigh sensitivity of 1211.11 μA cm−2 μM−1 enables detection of glucose at concentrations relevant to human sweat (typically 0.1–0.5 mM), surpassing conventional metal oxide FET sensors by an order of magnitude; this directly addresses the clinical need for non-invasive monitoring with sufficient signal-to-noise ratio for continuous tracking. • • The FET operates under negative back-gate voltage, exploiting subthreshold characteristics to amplify the enzymatic oxidation signal; this operational mode reduces power consumption and enhances sensitivity, critical for wearable device integration where battery life and heat dissipation are constrained. • • Liquid-metal-derived ultrathin SnO2 films provide a high density of surface hydroxyl groups for stable GOX immobilization, yielding a biosensor with near-specific glucose detection amidst other sweat components (e.g., lactate, uric acid, ascorbic acid); this mitigates the selectivity bottleneck that plagues enzyme-free and carbon-based sensors. • • The device demonstrates functionality in human sweat samples, validating its practical utility for non-invasive monitoring; however, long-term stability and reproducibility under physiological pH and temperature fluctuations remain to be quantified, posing a barrier to clinical translation.