Syntheses And Properties Of Hypochlorous Acid Fluorescence Probes Based On Thiocarbamate

Hypochlorous acid(HClO/ClO~–),as a typical sterilization and disinfection product and an important reactive oxygen species,is commonly used in our daily life and plays a key role in human’s physiological activities.In vivo,ClO~–is mainly produced by the myeloperoxidase catalysis of chlorine ions and hydrogen peroxide and normal expression of ClO~–contributes to the cell homeostasis.However,excessive production of ClO~–in cells may lead to oxidative stress response,thereby causing diseases including leukemia,nephritis,tumors and atherosclerosis.Therefore,to understand the detailed relationship between ClO~–and diseases,developing a simple,effective,accurate,method for ClO~–rapid detection in vivo is of great significance.In this paper,three fluorescence probes,L1,L2,and L3 were designed and synthesized based on ICT(Intramolecular charge transfer)mechanism,using thiocarbamate as the group of ClO~–on the framework of quinoline,thiazole and indole derivatives,respectively.The structures of L1,L2,and L3 have been characterized by nuclear magnetic resonance(NMR)and high resolution mass spectrometry(HRMS),and the spectral properties these three fluorescence probes were investigated by UV-Vis and fluorescence spectra,respectively.In the presence of ClO~–,the thiocarbamate group of L1 and L2 was removed because of the strong oxidation properties of ClO~–,leading to the hydroxyl-contained recognition product,while ClO~–was proved to selective oxidize C=C of L3 to form type of recognition products(ketone and aldehyde derivatives).Both of these two kinds of mechanisms have been verified by HRMS and fluorescence spectra.In vitro,L1,L2,and L3 exhibited highly selective and“naked-eye”detection abilities towards ClO~–without the interferences of other species including common anions,reactive oxygen/nitrogen species.Specifically,the limit of detection(LOD)of L1 towards ClO~–was calculated to be 299.7 n M and the response time was less than 10 s.More importantly,this probe was applicable in a wide p H range(3.0-11.5).L2 was found to be able to response ClO~–in less than 50 s under the p H range of 6.60-7.60,and the LOD of L2 was 3.22μM.L3 was only sensitive to ClO~–in weak base conditions with a LOD of 23.8 n M.The applicable p H range is 7.00-7.60and the response time of L3 was found to be less than 40 s.Considering the excellent properties of L1,L2,and L3,these three fluorescence probes were successfully applied to detect exogenous and endogenous ClO~–in zebrafish and nude mice.