The sensor presented in this article consists of a nanostructured tin oxide as high sensitive material and an efficient high temperature microhotplate. Tin oxide nanoparticles are in suspension in a solvent (colloidal solution) and then are deposited by contactless methods such as microinjection on a new efficient microhotplate. The microhotplate has been developed with high electrical and mechanical stabilities up to 650°C with a low power of consumption (< 80mW) and allows an efficient control of temperature, useful for detection of gases. In this work, the gas sensor developed is exposed to different polluting gases like carbon monoxide, propane and nitrogen dioxide at different temperatures to determine the optimum operating temperatures which P. Yoboue, A. Konaté, O. Asseu, P. Tety and P. Ménini 42 allow obtaining the highest sensitivity for each gas. It is also demonstrated that these gas sensors present a better sensitivity and above all a better stability compared to commercial metal oxide gas sensors.