The high porous surface of tungsten oxide (WO3) gas sensor was deposited by physical vapor deposition (PVD) technique on interdigital FTO-glass substrate deposited by DC sputtering method through the change of substrate position. In order to investigation the effect of Au nanoparticles as dopant on gas sensor performance, these nanoparticles were decorated by PVD method on the surface of high porous WO3 gas sensor. The crystal structure and morphology properties of WO3 gas sensor were evaluated by XRD and FESEM. Furthermore, the NO2 gas sensing properties for three samples including common, high porous and Au decorated high porous surfaces were detected. The Au decorated high porous gas sensor exhibited much higher response, shorter response and recovery time and excellent selectivity to NO2 gas at an operating temperature of 130 °C in compared to other samples. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.