Manufacturing In2O3/PVP fibers, by sol gel method coupled with the electrospinning technique, have been obtained In2O3 nanostructures. The morphological and microstructural properties of as spun and annealed samples have been examined using Thermo Gravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC), X-Ray Diffraction analysis (XRD) and Scanning Electron Microscopy (SEM). Characterization results provided clear indications of the formation of different In2O3 nanostructures after annealing by changing the solvent system utilized for the electrospinning process. The sensing characteristics of the In2O3 nanostructures synthesized have been evaluated for the monitoring of nitrogen dioxide at room temperature in the dark, under continuous ultra-violet (UV) illumination and under pulsed UV illumination (provided only during the recovery time). The effect of In2O3 nanostructure morphology and UV radiation has been investigated and discussed. The better sensing performances (high response and very short recovery time) were registered when the sensors were irradiated with pulsed UV light. (C) 2014 Elsevier B.V. All rights reserved.