Two-in-One Sensor Based on PV4D4-Coated TiO<sub>2</sub> Films for Food Spoilage Detection and as a Breath Marker for Several Diseases
Mihai Brinza,
Stefan Schröder,
Nicolai Ababii,
Monja Gronenberg,
Thomas Strunskus,
Thierry Pauporte,
Rainer Adelung,
Franz Faupel,
Oleg Lupan
Affiliations
Mihai Brinza
Center for Nanotechnology and Nanosensors, Department of Microelectronics and Biomedical Engineering, Technical University of Moldova, 168 Stefan cel Mare Av., MD-2004 Chisinau, Moldova
Stefan Schröder
Department of Materials Science, Chair for Multicomponent Materials, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany
Nicolai Ababii
Center for Nanotechnology and Nanosensors, Department of Microelectronics and Biomedical Engineering, Technical University of Moldova, 168 Stefan cel Mare Av., MD-2004 Chisinau, Moldova
Monja Gronenberg
Department of Materials Science, Chair for Functional Nanomaterials, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany
Thomas Strunskus
Department of Materials Science, Chair for Multicomponent Materials, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany
Thierry Pauporte
Institut de Recherche de Chimie Paris—IRCP, Chimie ParisTech, PSL Université, 11 rue Pierre et Marie Curie, 75231 Paris, Cedex 05, France
Rainer Adelung
Department of Materials Science, Chair for Functional Nanomaterials, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany
Franz Faupel
Department of Materials Science, Chair for Multicomponent Materials, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany
Oleg Lupan
Center for Nanotechnology and Nanosensors, Department of Microelectronics and Biomedical Engineering, Technical University of Moldova, 168 Stefan cel Mare Av., MD-2004 Chisinau, Moldova
Certain molecules act as biomarkers in exhaled breath or outgassing vapors of biological systems. Specifically, ammonia (NH3) can serve as a tracer for food spoilage as well as a breath marker for several diseases. H2 gas in the exhaled breath can be associated with gastric disorders. This initiates an increasing demand for small and reliable devices with high sensitivity capable of detecting such molecules. Metal-oxide gas sensors present an excellent tradeoff, e.g., compared to expensive and large gas chromatographs for this purpose. However, selective identification of NH3 at the parts-per-million (ppm) level as well as detection of multiple gases in gas mixtures with one sensor remain a challenge. In this work, a new two-in-one sensor for NH3 and H2 detection is presented, which provides stable, precise, and very selective properties for the tracking of these vapors at low concentrations. The fabricated 15 nm TiO2 gas sensors, which were annealed at 610 °C, formed two crystal phases, namely anatase and rutile, and afterwards were covered with a thin 25 nm PV4D4 polymer nanolayer via initiated chemical vapor deposition (iCVD) and showed precise NH3 response at room temperature and exclusive H2 detection at elevated operating temperatures. This enables new possibilities in application fields such as biomedical diagnosis, biosensors, and the development of non-invasive technology.
