Construction And Performance Study Of Biological Thiol Fluorescent Probe

Biological thiols mainly refer to cysteine(Cys),homocysteine(Hcy)and glutathione(GSH).They play an important role in the organism,such as the conversion and transmission of intracellular signals,the synthesis of proteins,and the maintenance of physiological balance in the organism.The content and role of different biological thiols in organisms are different: the content of cysteine in cells is30-200 μM,which is mainly involved in the affinity reaction;the content of homocysteine in cells is only 5-13 μM,mainly involved in the metabolic process;the content of glutathione in the cell is 1-10 m M,which mainly plays a role in maintaining the redox balance.Abnormal biological thiols can cause many diseases.Therefore,the development of accurate,effective,simple and rapid fluorescent probes for identifying biological thiols has important scientific value and physiological significance.In this paper,based on the recognition sites of dinitrobenzenesulfonyl,dinitrophenyl ether and carbon-carbon double bonds,combined with thiazole and indole derivatives,three fluorescent molecular probes for specific recognition of biological thiols were designed and synthesized,P2,Z2 and W2.The structure of the probe is characterized by means of high-resolution mass spectrometry,nuclear magnetism,etc.,the spectroscopic properties of the probe are studied using ultraviolet and fluorescence machines,and the recognition mechanism of the three is studied by high-resolution mass spectrometry.The probes P2 and Z2 undergo nucleophilic substitution reactions with Cys to remove the corresponding recognition groups.The probe W2 undergoes a Michael addition reaction with the sulfhydryl group in Hcy,destroying the conjugation system of the probe structure.Under simulated physiological conditions,P2 and Z2 can specifically recognize Cys,and probe W2 can specifically recognize Hcy,and has a color change,so it has the "naked eye" recognition effect.At the same time,other ions did not significantly interfere with the recognition of Cys and Hcy.Probes P2 and Z2 can effectively recognize Cys under neutral and alkaline conditions,and probe P2 has a lower detection limit for Cys(LOD=0.87 μM)and a shorter response time(t=70 s).The detection limit of needle Z2 for Cys is 26.4 μM,and the response time is short(<1 min).Probe W2 has a large p H range(3-11),the detection limit of Hcy is 40.5 μM,and the response time is 100 s.Based on the above spectral performance test results,it can be successfully applied to the qualitative detection of biological thiols in Hela cells.These three probes have great application prospects for the qualitative and quantitative detection of biological thiols in vivo.