Metal Oxide Nanowire Gas Sensors: Application of Conductometric and Surface Ionization Architectures

The present work reports on conductometric gas sensors based on metal oxide nanostructures developed in our laboratory in Brescia (Italy) showing their potentialities in term of sensitivity, selectivity and stability toward different molecules, including odorous compounds such as ammonia and hydrogen sulfide. The capability of these devices to discriminate different odors is further reported integrating these devices into an electronic nose system, and applying it to food quality control, in particular, to identify coffee samples contaminated with mold. Finally, preliminary results obtained with surface ionization gas sensors are reported, discussing their working principle and differences with respect to conductometric gas sensors, suited to further address selectivity.