Nb2O5 thin film-based conductometric sensor for acetone monitoring

Nowadays, effective detection of gases at ppm and ppb level is of crucial importance in a wide range of applications, such as industrial processes, environmental monitoring, public security and medical investigation. Several sensor types have been developed in last decades, among them the metal oxide gas sensors are the most promising for low-cost and portable applications, where good sensitivity and selectivity, together with small size are important constraints. The proposed conductometric gas sensor has been manufactured depositing a Nb2O5 thin film by plasma sputtering on a commercial alumina substrate with platinum interdigitated electrodes and heater which size is 3 mm x 6 mm with a thickness of 1 mm. The Nb2O5 thin film has been characterized by FE-SEM and XPS analysis. The sensor performance towards several target gases have been evaluated employing an experimental setup specifically developed for the characterization of gas sensors. The sensor exhibits good sensitivity towards acetone, a bio-marker found in human breath of diabetes patients. This makes the sensor promising in the noninvasive diagnosis of this kind of disease.