Counmarin-based Fluorescent Probes For The Detection Of Hydrogen Sulfide/Biothiols And Biological Imaging Application

Fluorescent probes have been widely used as biosensors in chemical and biological research fields due to their advantages of simple operation,high sensitivity and good biocompatibility.Hydrogen sulfide?H₂S?and biothiols are important reactive sulfur species?RSS?.In biological systems,biothiols mainly include cysteine?Cys?,homocysteine?Hcy?and glutathione?GSH?.The abnormal content of hydrogen sulfide and biothiols in the body can easily lead to a series of diseases.Therefore,being able to detect hydrogen sulfide and biothiols in organisms efficiently and accurately is of great significance for the early diagnosis and clinical treatment of diseases.However,due to the similar chemical properties of hydrogen sulfide and biothiols,it is difficult to distinguish and detect hydrogen sulfide and biothiols by using a fast and simple method.This paper mainly uses the difference in nucleophilicity of H2 S and biothiols to design and synthesize several fluorescent probes for distinguishing detection of H2 S and biothiols.At the same time,It realizes the "naked eye" detect H2 S by utilizing the colorimetric difference between the products of H2 S and biothiols with the probe,and studies the probe detection of H2 S and biothiols in living cells.The specific research works are as follows:?1?The fluorescent probe 2-1 using coumarin derivative as fluorophore and sulfonate as recognition site was designed and synthesized for the detection of H2 S.Probe 2-1 emited a weak yellow fluorescence at 556 nm.When Na HS was added,strong red fluorescence was emitted at 610 nm.Moreover,it showed good selectivity for H2 S in selectivity experiments,and realized the specific detection of H2 S by a ratio-type fluorescent probe.At the same time,the solution changed from light yellow to purple,enabling "nude eye" detection of H2 S.In addition,cell experiments showed that probe 2-1 can be used to detect H2 S in He La living cells.?2?The fluorescent probe 3-1 using coumarin derivative as a fluorophore and nitrobenzoxazole?NBD?as a reactive group to detect the detection of Cys / Hcy and GSH / H2 S was designed and synthesized.The fluorophore fluorescence of probe 3-1 was quenched.When Cys / Hcy was added to the system,a substitution-Smiles rearrangement reaction occurred.Probe 3-1 emited Fluorescent blue and green.With the addition of GSH / H2 S,the substitution reaction of the-SH attack ether bond occurred,and only cyan blue fluorescence was observed due to rearrangement could not occur.Achieve fluorescence discrimination between Cys / Hcy and GSH / H2 S.However,with the addition of Na HS,the solution changed from colorless to purple,which realized visual discrimination and detection of H2 S.At the same time,the probe had been successfully applied to detect Cys / Hcy and GSH / H2 S in living cells.?3?The "turn-on" fluorescent probe 4-1 with coumarin derivatives as fluorophores was designed and synthesized.Probe 4-1 introduced both aldehyde and Ts-ester bonds as recognition sites for Cys and H2 S,respectively.Due to the different reaction sites,the optical properties of Cys and H2 S products were different,which could realize the detection of Cys and H2 S.