Utilizing an in-Situ Polymerized PANI-Bi₂O₃ Composite as a Room-Temperature Trimethylamine Sensor

A novel category of materials, including hybrid, heterojunction, composite etc., confirms exceptional versatility for applications in advanced electrical, optical, and chemical sensing devices. This study presents a controlled in-situ polymerization method to create a cost-effective and highly efficient polyaniline-bismuth oxide (PANI-Bi₂O₃) composite for a trimethylamine (TMA) gas-sensing platform. TMA demonstrates remarkable response (S = 1247%) which is 2.28 fold greater than pristine PANI, selectivity among 19 deadly volatile organic chemicals at room temperature (RT, 25 ± 1 °C) with rapid response time (5 s), recovery time (37 s), and lower detection limit (10.4 ppb). Furthermore, throughout a span of 90 days, it sustains its function, confirming a remarkable consistency. Research supported by theoretical calculations and post-exposure spectroscopic analysis indicated that the improved selectivity for TMA mostly results from decreased PANI-Bi₂O₃ composite, greater interfacial coupling, and elevated adsorption energy. The PANI-Bi₂O₃ combination merits considerable attention for its ability to assess food freshness through the detection of microbial volatile organic compounds (MVOCs).