Abstract
Concentrations of volatile organic compounds (VOCs) in exhaled and transdermal gases are changed depending on disease and metabolic states. Imaging of spatial distribution of transdermal VOCs at specific sites enables the identification of areas of high degree of emission. Furthermore, evaluation of VOC release dynamics is expected to have applications in simple and non-invasive metabolic assessment and disease screening. We developed a biofluorometric ethanol imaging system (sniff-cam) using the oxidation reaction of alcohol dehydrogenase (ADH). The sniff-cam was composed of an ADH-immobilized mesh, a UV-LED sheet, and a sensitive CCD camera to image the fluorescence intensity (ex: 340 nm, fl: 490 nm) of reduced nicotinamide adenine nucleotide (NADH), a coenzyme produced by the oxidizing ethanol catalyzed by ADH. The performance of the system was evaluated by measuring various concentrations of standard gaseous ethanol (EtOH), and a quantitative range of 0.05-10 ppm-v was obtained, which enables transdermal EtOH gas concentration measurement. The system also made it possible to visualize the 2D distribution of EtOH gas concentration in the hand and arm after drinking alcohol, and to study the appropriate sites for monitoring alcohol metabolism.
https://ror.org/051k3eh31 
