Measurements of VOCs with a semiconductor electronic nose

Abstract

A semiconductor electronic nose with a sensor array of 15 elements has been fabricated by magnetron radio frequency sputtering technique for detecting various volatile organic compounds (VOCs) in a low concentration range from 50 to 250 ppm in air at 300°C. The main components of the array have been titanium oxide and tin oxide (the latter has been doped with different Pt doses) semiconductor oxides with different thicknesses. A good single classification for six tested VOCs (propanal, methyl ethyl ketone, octane, benzene, toluene, and chloroform) has been obtained from this electronic nose through the technique of principal component analysis. In general, good response times, sensitivity, and reproducibility values have been obtained for all sensors, but it is interesting to underline the sensitivity increases to these gases from sensors in which titanium oxide is used for their preparation.