Field-Effect Transistors Based on Hybrid Materials Derived from Conjugated Polymers Toward Sensors for Environmental...

Conjugated polymer-based hybrid materials (CPHMs) are emerging as highly promising active layers for organic field-effect transistor (OFET) sensors, combining flexibility, biocompatibility, solution-processability, and semiconducting properties with tunable optoelectronic characteristics and strong analyte interactions. These attributes make them ideal for sensitive, selective, and versatile detection of environmental parameters such as gases, humidity, and temperature. This review highlights recent progress in CP-derived OFET sensors, focusing on material design, device principles, and sensing mechanisms. Comparative analyses of polypyrrole, polyaniline, polythiophene, and derivatives reveal that molecular engineering, controlled film deposition, and hybridization markedly enhance charge-transport, stability, and responsiveness. For instance, PPy-based systems achieve improved conductivity and robustness, while P3HT-based OFETs demonstrate high-performance gas sensing, particularly for NH₃ and NO_x, with optimized response times and detection limits. Nanoporous and composite architectures further boost responsivity and adsorption kinetics, though challenges remain in scalable fabrication, environmental stability, and ultra-low-level detection under complex conditions. Beyond gas sensing, applications in humidity and temperature detection remain underexplored, offering significant opportunities for innovation. Future directions emphasize tailoring polymer properties, refining nanoscale morphologies, and advancing scalable OFET architectures to strengthen gas-polymer interactions. Overall, CP-based OFETs hold strong potential for next-generation, reliable, and scalable sensors for environmental and biomedical applications.