Surface-engineered polymer brush gate electrodes enable high-sensitivity label-free glucose detection via organic electrochemical transistor

• Polymer-brush-gated OECT enables enzyme-free, label-free glucose detection. • Solvent-controlled tubular poly(EDOT-FPBA) improves ion transport and sensitivity. • Sensor shows high selectivity and long-term stability in biological environments. • Wide detection range (0.001–40 mM) covers clinically relevant glucose levels. Non-enzymatic glucose detection remains challenging due to poor selectivity and instability in complex biological environments. Here, we developed an organic electrochemical transistor (OECT) incorporating a CH 2 Cl 2 -derived poly(EDOT-FPBA) gate to enhance glucose sensing performance. A solvent-controlled electropolymerization strategy was employed to construct an ordered polymer-brush architecture, enabling efficient ion transport and improved exposure of boronic-acid recognition sites. Structural and electrical characterizations confirmed the brush-like morphology and its strong gate modulation capability. The device exhibited a pronounced gate-voltage shift(ΔV G ) of ≈82.0 mV, a broad linear range (0.001–40 mmol⸱L -1 ), and a low detection limit (5.6 µmol⸱L -1 ), with interference below 15%, repeatability within a relative standard deviation of 4.6%, and serum recoveries of 92.0–107.4%. This strategy provides a promising route for developing low-voltage, enzyme-free OECT for reliable glucose monitoring in complex biological systems.