Polythiophene (PTP) coated SnO2 nano-hybrid particles have been synthesized using an ultrasound assisted in situ oxidative polymerization of thiophene monomers. Reference experiments have also been performed in the absence of ultrasound to clearly illustrate the effect of ultrasonic irradiations. FTIR results show broadening and shifting of peaks toward lower wave numbers, suggesting better conjugation and chemical interactions between PIP and SnO2 particles. Due to strong synergetic interaction between the SnO2 nanoparticles and polythiophene, this hybrid nanocomposite has the potential application as chemical sensors. It has been observed that PTP/SnO2 hybrid sensors could detect liquefied petroleum gas (LPG) with high sensitivity at room temperature. PTP/SnO2 hybrid composite containing 20 wt%SnO2 showed the maximum sensitivity at room temperature. The sensing mechanism of PTP/SnO2 hybrid nanocomposites to LPG was mainly attributed to the effects of p-n heterojunction between PIP and SnO2. (c) 2013 Elsevier B.V. All rights reserved.