Abstract
2-nonenal is a volatile chemical component of body odor, known for the correlation between its concentration and the degree of aging. Because the concentration of 2-nonenal changes according to the aging-related metabolism change, measuring 2-nonenal in skin gas has a potential on biochemical evaluation of aging. However, highly selective 2-nonenal sensor has not been developed so far. In this study, we developed a biofluorometric gas sensor (bio-sniffer) that utilize NADPH-dependent enone reductase (ER) for selective detection of 2-nonenal. This sensor detects 2-nonenal by measuring the decrease in autofluorescence of NADPH (ex: 340 nm, fl: 490 nm), which occurs when ER reduces the α, β-unsaturated bond of 2-nonenal. The ER biosensor consists of an ER-immobilized membrane and a fiberoptic NADPH fluorescence detection unit having UV-LED and photomultiplier tube. We evaluated the performance of the ER biosensor using the primary substrate, ethyl vinyl ketone (EVK), and target molecule, 2-nonenal.The selectivity of the ER biosensor on 2-nonenal was also evaluated. The experimental result showed that the ER biosensor can quantify EVK from 100 nM to 1 mM, and it also showed significantly high fluorescence signal on 2-nonenal compared to other aldehydes.
