A thiourea-based fluorescent chemosensor for bioimaging hypochlorite

A thiourea-based fluorescent turn-off chemosensor FHC was developed for recognizing hypochlorite. With the addition of hypochlorite to FHC, FHC displayed a specific desulfurization reaction of the thiourea group followed by the fluorescent quenching response. The fluorescent turn-off response of FHC to hypochlorite was very fast to finish within a few seconds. Detection limit of hypochlorite was determined to be 0.43 mu.M.FHC can be applied for the bioimaging of hypochlorite in both HeLa cells and zebrafish. Response process of FHC to hypochlorite, via the desulfurization of the thiourea moiety, was demonstrated, based on H-1 NMR titrations, ESI-mass, fluorescent and UV-vis titrations and DFT calculations. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.