A highly sensitive and selective gas-sensing material based on gold (Au)-functionalized tungsten oxide (WO3) composite nanofibers (NFs) has been fabricated under mild conditions by electrospinning (ES). Au nanoparticles (NPs)-decorated WO3 composite NFs were obtained by ES of the tungsten precursor (ammonium metatungstate hydrate) (AMT) and polyvinyl alcohol (PVA) solution followed by a two-step annealing treatment. The chemical and structural characterizations of the resulting composite nanofibers have been performed with various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and inductively coupled plasma optical emission spectrometry (ICP-OES). The gas-sensing properties of the WO3-Au composite NFs with different Au contents (0.01 M and 0.1 M) toward volatile organic compounds (VOCs) (such as n-butanol) have been studied. A discussion concerning the role of Au content and the operating temperature is given to optimize the sensitivity, the dynamic response-recovery behaviors and consequently the efficiency of the WO3-Au composite sensor. (C) 2015 Elsevier B.V. All rights reserved.