Ultra-efficient trimethylamine gas sensor based on Au nanoparticles sensitized WO₃ nanosheets for rapid assessment of seafood freshness

Trimethylamine (TMA) is an organic amine gas used as an important index to assess the seafood freshness. In this work, an ultra-efficient trimethylamine gas sensor was constructed by ultrasonic treatment loading of Au nanoparticles (∼4 nm) on WO₃ nanosheets prepared by solvothermal self-assembly method. The response of the sensor to 25 ppm TMA was as high as 217.72 (R_air/R_gas) at 300 ℃. In addition, the Au/WO₃ nanosheets sensor exhibited rapid response-recovery time (8 s/6 s), low detection limit (0.5 ppm), and high selective detection of TMA. Moreover, the composition of volatiles produced by decay of Larimichthys crocea (0–15 days) was examined, which proved that the detection of TMA by the Au/WO₃ sensor can evaluate the freshness of Larimichthys crocea. Such a magnificent gas sensing performance reveals that the Au/WO₃ sensor has remarkable application potential in rapid and non-destructive seafood freshness assessment on the spot.