Chemoresistive gas sensors for sub-ppm acetone detection

New sensors for detecting acetone directly in the exhaled breath have been developed. Several metal oxide materials, ZnO in different nano-morphologies, WO3 pure and Zr-loaded and TixSn1-xO2 solid solutions, have been considered for comparing the functional properties of the corresponding thick films with respect to the target gas. ZnO nano-sheets and bipyramidal nanoaggregates exhibited the large responses towards acetone, however ZnO aggregates of nanocrystals, Zr-WO3 and Ti(x)Sn(1-)xO(2) showed better performances as regards the influence of humidity on the acetone response.