Needle-Shaped WO₃ Nanorods for Triethylamine Gas Sensing

The accurate and rapid monitoring of triethylamine (TEA) is highly desired for human health, environmental protection, and food safety. Herein, we have fabricated a WO3 sample with a morphology of needle-shaped nanorods via a simple hydrothermal method and subsequent calcination. The WO3 needle-shaped nanorods with 5 μm length and 400 nm diameter possess a uniform and homogeneous morphology, which avails large-scale industrialization. The sensing based on needle-shaped WO3 nanorods exhibits an ultrasensitive response to TEA, with a response up to 6.7 toward 1 ppm TEA at 250 °C. The outstanding selectivity and repeatability are observed as well. The excellent sensing performance is tentatively attributed to the uniform and large-scale morphology, highly active C–N bonds in TEA, and the effective interaction between WO3 and TEA. Furthermore, the sensor is directly employed to monitor the TEA given off from a grass carp in 48 h, and a good linearity (R2 = 0.996) between the response and preserving time is obtained, proving its promising prospect in daily use. The architecture strategy opens an available route for large-scale practical fabrication of WO3 needle-shaped nanorods, and it is a pioneering attempt to apply the sensor for trace TEA detection in marine food safety testing.