Synthesis And Application Of Highly Selective Fluorescent Probes And Red Dyes

Highly selective fluorescent probe molecules are important tools of detecting and diagnosing of diseases in vivo.Therefore,it is of great significance to develop new fluorescent probes to solve the current problems.As fluorescent precursors of probe molecules,the development of dyes with superior photophysical properties is beneficial for bioimaging applications.Based on above,the main contents of the research are as follows:（1）A novel bifunctional fluorescent probe PBC1 was synthesized by introducing a phenothiazine moiety that specifically recognizes HCl O into a benzopyran-coumarin dye.This probe can solve the problem of poor selectivity of benzopyran-coumarin dyes in the detection of HCl O and SO₂.The probe PBC1 exhibited obvious red fluorescence at 610 nm following the addition of SO₂,and the fluorescence intensity gradually increased with the increase of SO₂ dosage.The detection limit was calculated to be 7.0n M（S/N=3）.The probe PBC1 exhibited green fluorescence at 485 nm with a detection limit of 13.0 n M after the addition of HCl O.The two fluorescence signals of HCl O and SO₂ are well separated（the wavelength difference between the green and red signals is 125 nm）.The probe PBC1can detect HCl O and SO₂ sensitively and selectively with fast response time.In addition,it was successfully applied to image HCl O and SO₂ in He La cells and zebrafish,and the two compounds could be distinguished by producing different fluorescent signals.（2）The colocalization ability of lipid droplets was increased by changing the length of different alkyl chains,while the strong intramolecular ICT effect enhanced the solvation effect.The push-pull fluorescent probe CDA1-4 was synthesized using different alkyl benzaldehydes as the donor and 3-cyano-4-methylcoumarin as the acceptor.The emission wavelength of the probe showed a significant red shift with the increase of solvent polarity,and the emission wavelength was linearly related to the solvent polarity in different solvents.Probes CDA1-4gradually improved the co-localization ability of lipid droplets with the increase of alkyl chains,and the polarity changes of cytoplasm and lipid droplets were observed at the same time.In addition,when cells were stimulated with large amounts of H₂O₂ and oleic acid to produce a stress response,the probe CDA4 monitored lipid droplet and cytoplasmic changes in dual-color imaging.（3）A new donor,5,10-dihydro-5,10-dimethylphenazine（abbreviated as MP）,was synthesized.MP series dyes increase the ICT effect by introducing MP groups as donors and different electron withdrawing groups as acceptors in coumarin and BODIPY,which solves the problem of short emission wavelength and small Stokes shift of coumarin and BODIPY dyes.MP series dyes have emission wavelengths above 650 nm and Stokes shifts in excess of 110 nm.The large conjugated system of the MP group itself can disperse electron density,avoid the risk of being oxidized,and have good photostability.Based on the good photophysical properties of the above MP dyes,we had also successfully applied them to cell imaging.98 pictures,11 tables,129 references.