iHWG-MOX: A Hybrid Breath Analysis System via the Combination of Substrate-Integrated Hollow Waveguide Infrared Spectroscopy with Metal Oxide Gas Sensors

• Published in: ACS sensors Vol. 5; no. 4; pp. 1033 - 1039
• Main Authors: Glöckler, Johannes, Jaeschke, Carsten, Kocaöz, Yusuf, Kokoric, Vjekoslav, Tütüncü, Erhan, Mitrovics, Jan, Mizaikoff, Boris
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 24-04-2020
• Subjects: Biosensing Techniques - methods; Breath Tests - methods; Gases - analysis; Humans; Spectrophotometry, Infrared - methods; metal oxide sensor; breath analysis; eNose; substrate-integrated hollow waveguide; breath diagnostics; iHWG
• ISSN: 2379-3694; 2379-3694
• DOI: 10.1021/acssensors.9b02554

According to their materials and operating parameters, metal oxide (MOX) sensors respond to target gases only by a change in sensor resistance with a lack in selectivity. By the use of infrared spectroscopy, highly discriminatory information from samples at a molecular level can be obtained and the selectivity can be enhanced. A low-volume gas cell was developed for a commercially available semiconducting MOX methane gas sensor and coupled directly to a mid-infrared gas sensor based on substrate-integrated hollow waveguide (iHWG) technology combined with a Fourier transform infrared spectrometer. This study demonstrates a sensing process with combined orthogonal sensors for fast, time-resolved, and synergic detection of methane and carbon dioxide in gas samples.