| Title: | Switchable sniff-cam (gas-imaging system) based on redox reactions of alcohol dehydrogenase for ethanol and acetaldehyde in exhaled breath |
| Author(s): | Iitani K; Hayakawa Y; Toma K; Arakawa T; Mitsubayashi K; |
| Address: | "Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan. Department of Biomedical Devices and Instrumentation, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan. Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan; Department of Biomedical Devices and Instrumentation, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan. Electronic address: m.bdi@tmd.ac.jp" |
| DOI: | 10.1016/j.talanta.2018.12.070 |
| ISSN/ISBN: | 1873-3573 (Electronic) 0039-9140 (Linking) |
| Abstract: | "Measuring the volatile organic compounds (VOCs) released from a human is a promising method for noninvasive disease screening and metabolism assessment. Selectively imaging multiple VOCs derived from human breath and skin gas is expected to improve current gas analysis techniques. In this study, a gas-imaging system (sniff-cam) that can be used to simultaneously image the concentration distribution of multiple VOCs, namely, ethanol (EtOH) and acetaldehyde (AcH), was developed. The sniff-cam was based on the pH-dependent redox reactions of nicotinamide adenine dinucleotide (NAD)-dependent alcohol dehydrogenase (ADH). The sniff-cam was constructed with a camera, two ADH-immobilized meshes, and a UV-LED array sheet. The ADH-immobilized mesh containing a solution of the oxidized form of NAD (NAD(+)) or reduced form (NADH) was used as an EtOH-imaging mesh and an AcH-imaging mesh, respectively. The distributions of the EtOH and AcH concentrations were visualized through the fluorescence of NADH (the excitation wavelength was 340?ª+nm; the emission wavelength was 490?ª+nm) occurring by the ADH-mediated redox reaction. First, the influence of pH on the activity of the redox reaction of ADH was measured, and then the quantitativeness and selectivity of the sniff-cam were evaluated. The ADH-mediated reactions of EtOH and AcH showed maximum activities at pH 9.0 and pH 6.5, respectively. The sniff-cam demonstrated not only a dynamic range (0.1-1000?ª+ppm for EtOH and 0.2-10?ª+ppm for AcH) for measuring EtOH and AcH in breath after drinking alcohol, but also displayed a high selectivity against other breath VOCs. Finally, EtOH and AcH in breath after drinking alcohol were measured simultaneously. A group with high activity of aldehyde dehydrogenase type 2 (EtOH = 143.3?ª++/-?ª+13.5?ª+ppm, AcH = 1.7?ª++/-?ª+0.2?ª+ppm) and a group with low activity (EtOH = 163.3?ª++/-?ª+28.0?ª+ppm, AcH = 8.4?ª++/-?ª+0.5?ª+ppm) displayed differences in the concentrations of EtOH and AcH contained in their breath samples, and the effectiveness of the developed method was confirmed and compared with previous results. It is suggested that the multiplexed sniff-cam in the future may be capable of selectively and simultaneously imaging various VOCs in human breath and skin gas by using multiple NADH-dependent enzymes" |
| Keywords: | Acetaldehyde/*analysis/metabolism Alcohol Dehydrogenase/*metabolism Breath Tests Ethanol/*analysis/metabolism Fluorescence Humans Optical Imaging Oxidation-Reduction Saccharomyces cerevisiae/enzymology Volatile Organic Compounds/*analysis/metabolism Alcoh; |
| Notes: | "MedlineIitani, Kenta Hayakawa, Yuuki Toma, Koji Arakawa, Takahiro Mitsubayashi, Kohji eng Netherlands 2019/02/18 Talanta. 2019 May 15; 197:249-256. doi: 10.1016/j.talanta.2018.12.070. Epub 2018 Dec 27" |
