Nanostructure-gated organic electrochemical transistors for accurate glucose monitoring in dynamic biological pH conditions.

Non-invasive, real-time, and continuous monitoring of trace amounts of glucose in near-neutral biofluids is significant for the daily care and treatment of diabetic patients or people with suboptimal health status. Despite improved sensing performance with novel low-dimensional materials or porous structures in various enzymatic and non-enzymatic electrochemical glucose sensors, they still suffer from high cost, poor long-term stability, and performance fluctuations in varied temperature and pH. This work synergistically combines an Au-modified porous laser-induced graphene (LIG) gate electrode with an organic electrochemical transistor (OECT) to create a flexible non-enzymatic glucose sensor. The resulting OECT-based non-enzymatic glucose sensor exhibits significantly enhanced sensitivity in near-neutral biofluids, the limit of detection (LOD) (0.08 μM in pH = 7.4), excellent stability over time (degradation of ∼10 % in 180 days) and against temperature changes (30 °C-40 °C), self-pH calibration capabilities, and uncompromised sensing performance with shrinking sizes. The highly consistent laser patterning technique and in situ galvanic reduction process for electrode modifications not only provide a simple yet versatile approach to creating low-cost, compact sensing platforms for precise and real-time sweat glucose measurements but also support scalable production, allowing the correlation study of key biomarkers in sweat and blood.