Authors: M. Righettoni, A. Tricoli, S. Gass, A. Schmid, A. Amann, S.E. Pratsinis
Affilation: ETH Zurich, Switzerland
Pages: 1 - 3
Keywords: breath analysis, acetone, diabetes, gas sensors
Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes. Here, a portable acetone sensor consisting of flame-deposited and in-situ annealed, Si:WO3 nanostructured films was developed. The chamber layout (e.g. volume, flow rate) and operating conditions (e.g. sensing temperature) have been optimized resulting in low limit of detection (~ 20 ppb), high selectivity to ethanol and short response times (~ 15 s) at realistic relative humidities as in the human breath. Furthermore, the sensor response was robust against variations of the exhaled breath flow rate facilitating application of these sensors to breath analysis. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS) resulting in good qualitative and quantitative agreement. The influence of physical activity and breath isoprene concentration on the sensor response were investigated in detail for the end tidal exhalation volume during continuous breathing. Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques.
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