In2O3-SnO2 composite nanofibers are synthesized via an electrospinning method and coated with La0.7Sr0.3FeO3 nanoparticles. Trimethylamine sensors are fabricated from the coated nanofibers and investigated at various conditions of different humidity. High response and short response/recovery times are obtained at 80 degrees C. The response is around 8.1 to 1 ppm trimethylamine, and the response and recovery times are about 1 and 6 s, respectively. Especially, the sensors show good humidity-resistant ability. The response only decreases to 6.3 for 1 ppm trimethylamine at 85% RH (25 degrees C). These characteristics would make the sensors good candidates for trimethylamine detection in practical applications. (C) 2014 Elsevier B. V. All rights reserved.