Pure In2O3 and solid state solution In2-xNixO3 nanofibers with different Ni-doping concentration were prepared via electrospinning method. Sensor based on In2-xNixO3 nanofibers with 6 (mol)% Ni-doping concentration exhibited the highest response, good selectivity and low detectable concentration limit down to ppb levels of NO2 at a relatively low temperature of 90 degrees C. These properties make the In2-xNixO3 nanofibers good candidates for NO2 detection. (C) 2013 Elsevier B.V. All rights reserved.