This work presents a new route to enhance the sensitivity of nanocrystalline TiO2 fibers based gas sensors. Pure and Pd-doped TiO2 nanofiber mats were synthesized by electrospinning and subsequent calcination. Highly porous fibrillar morphology was observed in the resultant nanocrystalline TiO2 fibers. In addition to anatase TiO2 crystallites, tiny (similar to 2 nm) PdO crystallites were observed in the Pd-doped TiO2 fibers. The sensors using Pd-doped TiO2 fibers showed promising gas sensing characteristics, such as low operation temperature (180 degrees C) and sufficient gas response (R/R-omicron = 38 to 2.1 ppm NO2). The techniques outlined here offer new means for preparing novel metal-oxide nanofibers with catalytic dopants. (C) 2010 Elsevier B.V. All rights reserved.