title: Bio-sniffer (gas-phase biosensor) with secondary alcohol dehydrogenase (S-ADH) for determination of isopropanol in exhaled air as a potential volatile biomarker.
abstract: Exhaled breath analysis has attracted lots of researchers attention in the past decades due to its advantages such as its non-invasive property and the possibility of continuous monitoring. In addition, several volatile organic compounds in breath have been identified as biomarkers for some diseases. Particularly, studies have pointed out that concentration of isopropanol (IPA) in exhaled air might relate with certain illnesses such as liver disease, chronic obstructive pulmonary (COPD), and lung cancer. In this study, a highly sensitive and selective biochemical gas sensor (bio-sniffer) for the breath IPA concentration determination was constructed and optimized. This bio-sniffer measures the concentration of IPA according to the fluorescence intensity of oxidized nicotinamide adenine dinucleotide (NADH), which was produced by an enzymatic reaction of secondary alcohol dehydrogenase (S-ADH). The NADH detection system employed an UV-LED as the excitation light, and a highly sensitive photomultiplier tube (PMT) as a fluorescence intensity detector. A gas-sensing region was developed using an optical fiber probe equipped with a flow-cell and enzyme immobilized membrane, and connected to the NADH measurement system. The calibration range of the IPA bio-sniffer was confirmed from 1ppb to 9060ppb that was comparable to other IPA analysis methods. The results of the analysis of breath IPA concentration in healthy subjects using the bio-sniffer showed a mean concentration of 16.0ppb, which was similar to other studies. These results have demonstrated that this highly sensitive and selective bio-sniffer could be used to measure the IPA in exhaled air, and it is expected to apply for breath IPA research and investigation of biomarkers for clinical diagnosis.
authors.affiliation: Graduate school of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Po-Jen
authors.initials: PJ
authors.lastname: Chien
authors.affiliation: Graduate school of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Graduate school of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Tsujii
authors.affiliation: 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.
authors.forename: Ming
authors.initials: M
authors.lastname: Ye
authors.affiliation: 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.
authors.forename: Koji
authors.initials: K
authors.lastname: Toma
authors.affiliation: 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.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Arakawa
authors.affiliation: Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-35 Yamate-Cho,Yamate-Cho, Suita-Shi, Osaka, 564-0836 Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Iwasaki
authors.affiliation: Graduate school of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, 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.
authors.forename: Kohji
authors.initials: K
authors.lastname: Mitsubayashi
mesh_terms: D019840:2-Propanol / Q000032:analysis* / Q000378:metabolism; D000328:Adult; D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D015374:Biosensing Techniques / Q000295:instrumentation*; D001944:Breath Tests / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D015003:Yeasts / Q000201:enzymology*; D055815:Young Adult
chemical_list: D004800:Enzymes, Immobilized; D000429:Alcohol Oxidoreductases; C025192:isopropanol dehydrogenase (NADP); D019840:2-Propanol
keywords: Biosensor; Gas sensor; Isopropanol vapor; NADH; Secondary alcohol dehydrogenase; Volatile organic compounds