Quantification of in vitro malodor generation by anionic surfactant-induced fluorescent sensor property of tryptophan

In this article, we report tuning of the sensory capability of an amino acid (tryptophan) in a biomimicking anionic micellar nano cage. It has been shown that anionic surfactant concentration dictates the sensing behavior of tryptophan toward body malodor component (butyric acid) generated by bacterial degradation of tributyrin. We have proposed a fluorescence quenching mechanism that is based on short-chain fatty acid (SCFA) proximity with tryptophan present at the micelle-water interface. Anionic surfactant-induced fluorescent sensor activity of tryptophan exhibits high sensitivity (detection limit up to 10 μM) and specific selectivity (toward SCFA, < C12) in aqueous solution. We also determined antibacterial efficacy of various zinc salts based on the sensory activity of tryptophan, which has been correlated with the established resazurin assay.