The Design,Syntheses And Application Of New Fluorescence Swjtus For Biothiols

Biothiols,such as cysteine(Cys),homocysteine(Hcy)and glutathione(GSH),play important roles in redox homeostasis,biocatalysis,metal complexes and post-translational modification.At present,there are many methods for the detection of biothiols,such as high performance liquid chromatography(HPLC),electrochemical detection and mass spectrometry(ECMs),capillary electrophoresis(CE),etc.Compared with these methods,fluorescence method is relatively simple,sensitive and mature.Therefore,it is necessary to develop effective fluorescent SWJTUs for efficient and specific recognition of intracellular biothiols.Therefore,three novel fluorescent SWJTUs were designed and synthesized,which can be used to detect intracellular biothiols.The specific work is as follows:(1)SWJTU-1 was designed and synthesized with fluorescein as fluorescent group and propionyl bromide as recognition group.Under the condition of DMSO: HEPES = 2 : 3(v/v,pH 7.4),the UV spectrum,fluorescence spectrum,response time,pH,concentration changes and other conditions were determined.The application of SWJTU-1 in living cells showed that it could be used to detect biological thiols under physiological conditions.The detection limit of Cys is 6.51 ?M.(2)The near-infrared fluorescent SWJTU-2 was designed and synthesized by using isophorone as luminescent group and acryloyl group as recognition group.Firstly,we studied the best solvent system of SWJTU-2 and determined the DMSO / PBS system as the best experimental condition;Therefore,in DMSO: PBS = 4 : 1(v/v,pH 7.4)buffer solution,the UV and fluorescence spectra of cysteine recognized by SWJTU-2 were analyzed;The response time of SWJTU-2 was investigated;The effect of pH on the stability of SWJTU-2and concentration titration were studied;The luminescent mechanism of SWJTU-2 was studied by density functional theory and nuclear magnetic titration;Biological imaging was performed in HeLa cells.The results show that the emission wavelength of SWJTU-2 is up to 693 nm,the stoke shift is up to 143 nm,and the detection limit is as low as 1.29 ?M.The specific recognition of cysteine can be realized in cellssolution system.(3)the solvent screening of SWJTU-3,DMSO: PBS = 11 : 9(v/v,pH 7.4)buffer solution was determined.The ultraviolet spectrum and fluorescence spectrum of cysteine recognized by SWJTU-3 were analyzed;Then the reaction time of SWJTU-3 with Hcy was investigated;The effect of pH on the stability of SWJTU-3 and concentration titration.The results showed that SWJTU-3 had faster detection time and lower detection limit,and could specifically and efficiently detect Cys in only 2 minutes,with detection limit as low as 0.43 ?M? Finally,SWJTU-3 was applied to HeLa cells for bioimaging...