Application of a gas sensor microarray to human breath analysis

A novel type of metal oxide gas sensor array was used in order to develop a cheap instrument for a quick self-check of breath odor quality. The sensor array consists of 40 monolithic sensor elements whose different sensitivity was achieved by gradient techniques. SnO2 and WO3 coatings as detection layers were tested at different temperatures in order to optimize the system to a sensitive and fast detection of malodor components like NH3, H2S, CH3SH, indole and putrescine, with little cross-sensitivity to ethanol and humidity.