Polycrystalline nanostructured thin films of n-type ZnO and Sb doped ZnO with doping at 1%, 3% &5% possessing tailored electrical and optical properties are prepared by vacuum evaporation followed by air annealing and their application as gas sensor is evaluated. Doped films show substantial improvement in response time and sensitivity to Liquid Petroleum Gas, with fastest response similar to 20 s for 5% Sb doped samples. Doping enhances optical bandgap, transmittance, photoresponse and electrical conductivity. Carrier concentration and mobility are maximum for 5% doped, which corroborates the electrical conductivity variations for the doped samples which is also maximum for 5% doped. (C) 2016 Elsevier B.V. All rights reserved.