Fabrication of Bi2S3/ZnO nanocomposites for TEA gas sensors operating at room temperature: Towards seafood freshness detection during storage

Amine-based gases have become an important indicator for detecting the decay of seafood, especially during the transportation and storage process. Triethylamine (TEA) is continuously produced as a result of slow decay, therefore, detecting the release of TEA from the food spoilage to indirectly measure the freshness of seafood has become a crucial method. However, the current TEA sensors frequently encounter issues such as low sensitivity, poor selectivity, or the necessity for higher operating temperatures, all of which hinder their practical application in seafood quality detection. In our work, for the first time, the gas-sensitive response of Bi 2 S 3 to TEA at room temperature (25 ℃) was improved by the composite of ZnO nanoparticles. The response to 100 ppm TEA is 2.51, which is 3.7 times that of pure Bi 2 S 3. The response/recovery time is 49/270 s. The materials structure and composition were studied by the methods like XRD, SEM, XPS, FTIR, and TEM, and the surface area of the nanocomposites was 24.6 m 2 /g, which could provide more adsorption sites. Then a response mechanism was proposed based on those characterization results. Meanwhile, the experimental verification shows that the sensor have excellent selectivity, repeatability and stability. Finally, a TEA detection equipment was designed to effectively detect the TEA produced by decayed marine fish. This work reports the first example of fabrication Bi 2 S 3 /ZnO Nanocomposites for TEA Gas Sensors at room temperature, and thus it’s also the first report about the application of Bi 2 S 3 /ZnO gas sensor for food safety. The gathered results reveal great prospects of TEA gas sensors for the food quality monitoring during transportation and storage.