Flexible and Regenerable Organic Photoelectrochemical Transistors With MXene‐Induced Ohmic Interfaces for Dopamine Sensing

Abstract

ABSTRACT Flexible organic photoelectrochemical transistor (OPECT)‐based sensors hold promise for noninvasive healthcare monitoring; however, achieving the simultaneous integration of mechanical flexibility, high sensitivity, and regenerability remains a significant challenge. Here, we report a flexible and regenerable molecularly imprinted polymer based OPECT sensing platform that enables highly sensitive dopamine (DA) detection. An Ohmic heterostructured photogate (denoted as WMI) is constructed by intercalating conductive and mechanically flexible MXene nanosheets between oxygen‐vacancy‐rich WO 3 and In 2 S 3 , which synergistically promotes efficient charge transport. To enable imprinted sites regeneration, density functional theory calculations are employed to optimize monomer–template interactions, identifying the o‐phenylenediamine–DA complex as the most stable configuration for repeated binding–elution cycles. Integrating OPECT signal amplification with MIP‐based recognition, the device achieves combined attributes of wide dynamic range (1 pM–0.1 µM), a low detection limit of 0.72 pM, high selectivity, stability, and reproducibility. Furthermore, the flexible platform maintains stable photocurrent signals under varying bending angles, demonstrating its suitability for wearable applications. This work establishes a strategy for incorporating mechanically rigid semiconductors into flexible electrodes with regenerative sensing capability, opening broad opportunities for continuous, noninvasive healthcare monitoring.