Rare-earth ions (Pr3+, Dy3+, Y3+, Er3+, Lu3+) modified MoO3 quasi-core-shell nanorods for triethylamine monitor and fish decayed level assessment

• MoO 3 :x%RE 3+ quasi-core–shell nanorods are innovatively designed and constructed. • MoO 3 :RE 3+ quasi-core–shell nanorods are firstly used as gas sensors to detect TEA . • MoO 3 :1%Pr 3+ demonstrates a response 12.3 times higher than the MoO 3 gas sensor. • MoO 3 :1%Pr 3+ gas sensor is designed and employed to detect the decaying fish. • MoO 3 :1%Pr 3+ sensor shows ability of detecting TEA at low concentrations of 1 ppm. Triethylamine (TEA) is a poisonous organic gas that is typically found in spoiled or rotting seafood and is extremely harmful to humans and the environment. Thus, it is an urgent need to design a gas sensor for the detection of TEA. MoO 3 exhibits promising potential as a gas-sensitive material to detect TEA. To our knowledge, reports are relatively few on one-dimensional nanomaterials of rare earth (RE) element-doped MoO 3 for TEA gas sensors to improve sensing performance. Herein, MoO 3 :x%RE 3+ (RE 3+ = Pr 3+ , Dy 3+ , Y 3+ , Er 3+ , Lu 3+ ; x = 0, 0.5, 1, 3, 5) quasi-core-shell nanorods are successfully constructed by electrospinning and one-step calcined process. All samples have undergone transformation into gas sensors. After doping with RE ions, all MoO 3 :1%RE 3+ gas sensors exhibit higher response values to TEA than MoO 3 . MoO 3 :1%Pr 3+ quasi-core-shell nanorods gas sensor demonstrates superior gas-sensitizing properties, exhibiting a 12.3-fold increase compared with the response value of MoO 3 gas sensor, and extremely high selectivity, rapid response/recovery time, and prominent resistance to moisture. More importantly, the feasibility of MoO 3 :1%Pr 3+ quasi-core-shell nanorods gas sensor for seafood freshness assessment is verified via testing the amount of TEA produced by decaying seafood at different storage times under different storage temperature and humidity. The sensing mechanism of doping RE ions into MoO 3 is also proposed to improve the sensor performance. This work offers an innovative strategy to design and construct high-performance gas sensors to detect TEA. This work also has important significance in the application of rare earth materials in the realm of gas sensing.