Portable gas sensor for breath analysis

Marco Righettoni, Antonio Tricoli, SAMUEL GASS, Sotiris E. Pratsinis

ETH Zurich

     Abstract Number: 849
     Last modified: August 10, 2010

Abstract
The detection of acetone within human breath is a promising method for diagnosis of diabetes and possibly in the future even for blood glucose monitoring. Here, a portable highly sensitive acetone sensor based on a back-heated chemo-resistive detector has been developed. This device enables real-time measurements of ultra low acetone concentrations at ideal and realistic conditions (up to 90% relative humidity). The detector consists of 10 mol% Si-doped WO$_3 nanoparticle film synthesized by flame spray pyrolysis and directly deposited onto an alumina sensor substrate. The sensing properties (selectivity, detection limit, sensor response and recovery times) were investigated as a function of operating temperature (300 - 390°C), relative humidity, interfering analyte concentration (ethanol), and inlet flow-rate. The high sensor performance of Si-doped epsilon-WO$_3 nanoparticles obtained with a large heated chamber setup have now been successfully reproduced by this portable back-heated sensor prototype. Furthermore, it was shown that the sensor response remains unchanged regardless of inlet volumetric flow-rate. This portable and cost-efficient detector is a significant advance toward the diagnosis of diabetes by breath analysis.