Breath Analysis; Kidney Failure; Lung Cancer; Diabetes; Sensor Characterization; Gas Sensor; Nanostructured Materials
Güntner Andreas, Abegg Sebastian, Wegner Karsten, Pratsinis Sotiris (2018), Zeolite membranes for highly selective formaldehyde sensors, in Sensors and Actuators B: Chemical
, 257, 916-923.
Güntner Andreas, Sievi Noriane, Theodore Jonathan, Gulich Tobias, Kohler Malcolm, Pratsinis Sotiris (2017), Non-invasive body fat burn monitoring from exhaled acetone with Si-doped WO3 sensing nanoparticles, in Analytical Chemistry
, 89, 10578-10584.
The aim of this request is to acquire a unique in operando characterization system to advance our chemoresistive sensors towards real breath analyzers applicable for non-invasive disease detection. Breath analysis offers a simple and rapid alternative to standard techniques such as blood analysis. Especially inexpensive hand-held breath analysis devices that do not require trained personnel bear the potential to drastically reduce medical diagnostic and monitoring costs and they could be applied by wide populations without medical personnel. More specifically, the ability to detect diseases already in an early stage and monitor their progress may improve medical treatment to a point-of-care therapy with higher chance for patient recovery and thus better quality of life. Our group focuses on the development of such portable breath analyzers consisting of compact metal-oxide sensors (funded by SNF grant #159763). We have significantly advanced this field by exploring unique sensing materials that feature unprecedented analyte selectivity, such as Cr/Si-doped e-WO3 (for acetone), Si-doped a-MoO3 (for NH3), Ti-doped ZnO (for isoprene) and a SnO2-based electronic nose (for formaldehyde). These sensors can be incorporated into portable breath analyzers and they are ready for extensive testing with humans for disease detection including diabetes, kidney failure and lung cancer. Despite their potential, two major challenges remain: (a) the validation of the sensors with real human breath and (b) understanding of the sensing mechanism to guide material optimization with respect to analyte sensitivity and selectivity and exploration of novel sensing materials. With the proposed system, both challenges can be addressed by combining well-established high performance mass spectrometry for reference gas analysis with particle structure (mobility analyzer) and electroceramic (piezoelectric) characterization to understand and optimize solid-gas interactions involved in breath sensor devices. We propose a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS), featuring high selectivity for all target analytes, lower limit of detection down to ppt concentrations. Such devices have been applied worldwide becoming increasingly recognized as the golden standard for real-time breath analysis. We had applied exactly such a system before (provided by Medical University of Innsbruck) to validate our breath acetone detector (e-WO3) revealing promising correlations between the sensor signal, breath acetone and blood glucose after overnight fasting. An additional mobility particle size selector and piezometer will be combined with the PTR-TOF-MS to provide better understanding of analyte interaction with the sensing film at the single particle level and enable systematic optimization of the sensors as particle aggregates exhibit stronger sensor response than particle agglomerates. The resulting high performance in operando characterization platform will be applied in projects for the development of breath analyzers for (A) non-invasive diabetes detection and blood glucose monitoring, (B) kidney malfunction assessment and hemodialysis monitoring and (C) lung cancer detection from breath and it will guide the (D) optimization of the sensing films. Most of these projects will involve extensive testing on humans in collaboration with the Department of Pulmonology at the University Hospital of Zurich. For these clinical trials, ethical permission has been granted already by the Kantonale Ethikkomission Zürich (KEK-ZH-Nr. 2015-0675). Our research for the development of portable breath analyzers is part of the flagship project Zurich Exhabolomics of Hochschulmedizin Zürich. This project is an interdisciplinary collaboration of highly motivated experts from both, technical and clinical areas of ETH Zurich, University Hospital Zurich, University of Zurich, University Children’s Hospital Zurich (Kispi) and EMPA. A key goal of this initiative is the development of instrumentation, devices and statistical data analysis to improve state-of-the-art breath analysis. We believe that there exists a unique constellation in Zurich for fundamental and translational research to pioneer the exploitation of exhaled breath analysis for medical diagnostics and patient management. The proposed system will contribute significantly to realize this vision since it will be made available for all collaborators within this network serving as a proven reference technique for breath studies.