Triethylamine gas sensor based on Au-functionalized CdGa2O4 for the practical detection of fish freshness

Triethylamine (TEA) is a volatile organic compound characterized as flammability, high toxicity and an ammonia-like odor. Due to its prevalent use in chemical production, the development of a highly sensitive and rapidly responding TEA detector holds significant importance for both environment safety and human health. Heterostructures have been shown to effectively enhance the sensitivity of sensors towards target gases, however the specific roles and dynamic evolution of the heterojunctions and semiconductor oxides remain inadequately understood during the gas response process. Herein, Au nanoparticle-modified CdGa₂O₄ microspheres were prepared by wet impregnation method and their gas sensing properties were examined. The 1.8Au-CdGa₂O₄-based sensor demonstrates a superior response value (S=128), a shorter response/recovery time (5/32 s) and a lower detection (1.54 ppb). Furthermore, practical experiments assessing fish freshness have confirmed that the sensor based on 1.8Au-CdGa₂O₄ has significant potential for real-world applications in fish freshness testing.