High-performance flexible NH3 sensor based on PANI/Ti3C2Tx composites for real-time fish spoilage detection

NH 3 is widely exist in food spoilage processes, and its concentration is closely related to environmental safety and human health. PANI is diffusely used in gas sensing due to its good sensing performance to NH 3 , but pure PANI sensors have problems such as low response to NH 3 and baseline drift. In order to improve the performance, Ti 3 C 2 T x , characterized by a large specific surface area and outstanding electron transport properties, was incorporated into polyaniline (PANI) to construct a Schottky junction-based composite sensor for ammonia detection. The incorporation of Ti 3 C 2 T x effectively enhances the protonation degree of PANI and introduces surface functional groups (−OH and − O) with strong affinity for NH₃ molecules. These synergistic effects result in a markedly improved gas-sensing performance compared to that of pristine PANI. The composite material demonstrates a significantly enhanced gas response of 267 % to 50 ppm NH₃ at room temperature, along with a lowered detection limit of 1 ppm. In addition, it exhibits excellent repeatability and selectivity, making it particularly suitable for monitoring ammonia emissions associated with food spoilage. In addition, the sensor still maintains stable operation under the condition of relative humidity of 70 %, showing excellent humidity resistance and broad practical application prospects.