Volatile organic compounds (VOCs) in breath and skin gas are promising samples for non-invasive and simple disease screening and metabolism assessment. In addition, simultaneous measurement of multiple VOCs helps to improve the examination quality and allows for more reliable disease screening and investigation of detailed metabolic pathways. In this study, we have developed a dual-target gas-phase biosensor (bio-sniffer) that allows for measurement of isopropanol (IPA) and acetone vapours, relevant VOCs for lipid metabolisms, by simply exchanging coenzyme solutions. The measurement exploited a reversible redox reaction that was catalysed by secondary alcohol dehydrogenase (S-ADH). IPA/acetone was oxidised/reduced together with reduction/oxidation of a coenzyme, oxidised (NAD⁺)/reduced (NADH) form of β-nicotinamide adenine dinucleotide, depending on surrounding pH (8.5/7.5). This reaction resulted in producing/consuming NADH which exhibited autofluorescence (λ_ex = 340 nm, λ_fl = 490 nm), by which IPA/acetone was measured. The characterization of the dual-target bio-sniffer showed the dynamic ranges for IPA and acetone vapour were 3.3–1000 ppb and 13.0–3000 ppb, respectively, which encompasses those in the breath of healthy people (IPA, 10–30 ppb; acetone, 200–900 ppb). Finally, the dual-target bio-sniffer was applied for measurement of IPA and acetone in the breath of healthy people. As with the standard IPA and acetone vapour, intermittent and repeated measurement of both VOCs in the breath was demonstrated. These results indicated that the dual-target bio-sniffer would be a useful tool to assess the lipid metabolism in detail by measuring temporal changes of IPA and acetone concentrations in the breath.

呼吸和皮肤气体中的挥发性有机化合物（VOC）是用于非侵入性和简单疾病筛查和代谢评估的有前途的样品。此外，同时测量多个VOC有助于提高检查质量，并允许更可靠的疾病筛查和详细代谢途径的研究。在这项研究中，我们开发了一种双目标气相生物传感器（bio-sniffer），可以通过简单地交换辅酶溶液来测量异丙醇（IPA）和丙酮蒸气，脂质代谢相关的VOC。该测量利用了仲醇脱氢酶（S-ADH）催化的可逆氧化还原反应。IPA /丙酮被氧化/还原，辅酶被还原/氧化，被氧化（NAD ⁺β-烟酰胺腺嘌呤二核苷酸）/还原形式（NADH），具体取决于周围的pH值（8.5 / 7.5）。该反应导致产生/消耗表现出自发荧光的NADH（_λex = 340 nm，_λfl＝ 490nm），由此测量IPA /丙酮。双目标生物嗅探器的特征表明，IPA和丙酮蒸气的动态范围分别为3.3–1000 ppb和13.0–3000 ppb，其中包括健康人呼吸中的那些范围（IPA，10–30 ppb；丙酮，200–900 ppb）。最后，将双目标生物嗅探器用于健康人呼吸中IPA和丙酮的测量。与标准IPA和丙酮蒸气一样，证明了呼吸中两种VOC的间歇性和重复测量。这些结果表明，双靶生物嗅探器将是通过测量呼吸中IPA和丙酮浓度的时间变化来详细评估脂质代谢的有用工具。