We have investigated electrical and gas sensitive properties of gas sensor based on carbon nanotubes (CNT) and carbon nanotubes modified by metal oxides (such as tin oxide and silicon oxide).  Also we  have find out that modification of  CNT by  metal oxides helps to  improve film`s adhesion to substrate, decrease electrical resistance, recovery time, working temperature , enhance gas sensitivity in comparison with sensitive elements based  only on CNT or metal oxides. Moreover experimental results showed that properties of composite material depend on concentration correlation of solutions. As a result we can get highest sensitivity of sensor element by choosing optimal relation between concentrations of solutions.

Keywords: Сarbon nanotubes, modification, tin oxide, silicon oxide, gas sensor