Breath Acetone Sensors as Non-Invasive Health Monitoring Systems: A Review

Finding a non-invasive, painless and simple method for monitoring of health parameters and early detection of physiological disorders is of utmost importance in today's world. Breath analysis has been attracted tremendous attention as a potentially powerful tool for studying the medical diagnosis diseases because of its noninvasive nature and capability of real-time monitoring. For metabolic monitoring, several candidates are attractive. As an example, acetone has been considered as a main breath biomarker for diabetes. In addition to diabetes, fat burn monitoring is another application for breath acetone. This article provides a comprehensive study on the state of the art research activities in gas sensor field. It mainly focuses on the metal oxide semiconductor based acetone sensors such as WO3, ZnO, SnO2, Fe2O3, In2O3, TiO2, Co2O3, NiO and etc. Several different type of acetone sensor technologies such as polymer based chemiresistors, mixed potential, optical and mass sensitive devices are presented as well. The effect of nano structures and morphology on response of sensors are discussed. The advantages and disadvantages of different techniques used for metal oxide semiconductor synthesis are also discussed. Finally, sensor arrays with different receptor materials and transducers for breath analyzing are discussed.