Synthesis And Application Of Pyrene-based Fluorescent Probes For Recognizing SO₃^2- And Biothiols

Sulfite(SO₃^2-),Cysteine?Cys?and homocysteine?Hcy?were a class of biologically active sulfur molecules containing sulfur atoms.They were ubiquitous in organisms,participated in various physiological functions and maintained system balance.However,the excess of them will cause a variety of diseases and cause physiological disorders.In this paper,pyrene was used as a fluorescent group to design and synthesize three fluorescent probes,which were used to detect SO₃^2-and Cys/Hcy,respectively.The details are as follows:Chapter 1: We designed and synthesized an enhanced fluorescent probe for detecting SO₃^2-?Probe 1?.Probe 1 had a weak emission at 420 nm in the DMSO/PBS?10 m M,p H 7.40,v/v,1/1?system.The fluorescence emission occurred a short-range redshift to 456 nm with the addition of SO₃^2-.Fluorescence spectrum data showed that the Probe 1 had stable spectral properties,high selectivity and anti-interference ability,good linearity,and extremely low detection limit?0.17 ?M?.Most importantly,the Probe 1 was successfully used to detect SO₃^2-in Hep G2 cells.Chapter 2: We constructed a complex?Probe 2?,that pyrene conjugated 2-chloropyridine by ?,?-unsaturated ketones.Probe 2 was obtained via one-step reaction with good yield.Cys/Hcy could break the space effect by nucleophilic addition to double bond of carbon-carbon,which made the system give a fluorescence emission.Furthermore,the study showed Probe 2 featured excellent selectivity and specificity for Cys/Hcy with a good reversibility.Moreover,Probe 2 suggested a potential for imaging in vivo,which was confirmed by the successful imaging of the probe in Hep G2 cells,zebrafish and Arabidopsis thaliana.Chapter 3: A new fluorescent probe capable of specifically recognizing Cys was synthesized based on pyrene and quinoline derivatives?Probe 3?.Under the excitation of 370 nm,Probe 3 itself had an emission peak at 560 nm,but when Cys was added,the emission peak blue shifted to 462 nm and the fluorescence intensity gradually increased.Meanwhile,the response time of Probe 3 was very fast,and the reaction could be completed within 2 minutes.The fluorescence imaging successfully verified that Probe 3 could detect endogenous and exogenous Cys in cells.