Breath acetone monitoring by portable Si:WO3 gas sensors

• Published in: Analytica chimica acta Vol. 738; pp. 69 - 75
• Main Authors: Righettoni, Marco, Tricoli, Antonio, Gass, Samuel, Schmid, Alex, Amann, Anton, Pratsinis, Sotiris E.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 13.08.2012; Elsevier
• Subjects: Acetone; Acetone - analysis; Analytical chemistry; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensor; Biosensors; Biotechnology; Breath Tests - instrumentation; Breath Tests - methods; Chemistry; Chemo-resistive gas sensor; Cross-sensitivity to humidity; Diabetes Mellitus - diagnosis; Exact sciences and technology; Flame spray pyrolysis; Fundamental and applied biological sciences. Psychology; General, instrumentation; Human; Humans; Illnesses; Limit of Detection; Metal oxide; Methods. Procedures. Technologies; Monitoring; Nanoparticles; Nanoparticles - chemistry; Oxides - chemistry; Portability; Relative humidity; Sensitivity and Specificity; Sensors; Silicon - chemistry; Spectrometric and optical methods; Tungsten - chemistry; Tungsten oxides; Various methods and equipments; Chemo-resistive gas sensor; Metal oxide; Nanoparticles; Cross-sensitivity to humidity; Flame spray pyrolysis; Biosensor; Relative humidity; State of the art; Temperature; Nanoparticle; In situ; Time; Metal; Signal; Gas flow; Detection limit; Quality; Diagnosis; Monitoring; Human; Pyrolysis; Device; Ultratrace compound; Concentration; Chemical sensor; Non destructive method; Volume; Transfer; Portable equipment; Detection; Application; Mass spectrometry; Gas detector; Acetone
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2012.06.002

[Display omitted] ► Portable sensors were developed and tested for monitoring acetone in the human breath. ► Acetone concentrations down to 20ppb were measured with short response times (<30s). ► The present sensors were highly selective to acetone over ethanol and water. ► Sensors were applied to human breath: good agreement with highly sensitive PTR-MS. ► Tests with people at rest and during physical activity showed the sensor robustness. Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (∼20ppb) with short response (10–15s) and recovery times (35–70s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. 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). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques.