PEDOT:PSS@WO₃ p-n heterojunction sensor for enhanced triethylamine detection at room temperature

Achieving high sensitivity and reliable detection of trace volatile organic compounds (VOCs) at room temperature remains a significant challenge for metal oxide semiconductor (MOS)-based gas sensors. In this work, we synthesized WO₃ microspheres and PEDOT:PSS@WO₃ (PPW) core-shell heterostructures through a combination of solvothermal treatment and in situ polymerization. The resulting composites were used as active sensing materials for triethylamine vapor detection at room temperature. The PPW-based sensors exhibited excellent TEA sensing performance, which may arise from the synergistic effects of the strong amine affinity of PEDOT: PSS, p–n heterojunction at the PEDOT:PSS/WO₃ interface and the core-shell structure that promotes efficient charge separation and transport. This study demonstrates the significant potential of PPW heterostructures for high-performance, room-temperature sensing of amine vapors and offers a promising strategy for next-generation gas sensor design.