The Synthesis Of Coumarin-BODIPY/Porphyrin Dyes And Investigation Of Their Spectral Properties

Recently, development of new fluorescent dyes for biomolecular sensing havebeen attracted great interesting to many chemical and biological scientists due to itshigh sensitivity, simplicity easy for implementation and minimal disturbance tobiological samples.In Chapter II, this paper have described and studied the photophysical propertiesof new series of coumarin-BODIPY conjugated compounds dyes then primarilyavaluated their utility in fluorenscence sensing. Boradiazaindacenes (BODIPY orboradipyrrin dyes) usually used as core for construction kinds of fluorenscent dyesare wildly applied in fileds like fluorescene labels, chemosensors, light harvestingsystems and photodynamic therapy. This was due to not only the good photophysicalproperties of BODIPY dyes, such as high quantum yileds, large extinctioncoefficients, and good photostable. But also their rich chemistry made the BODIPYcore easy chemical modified as well as their photophysical properties. Coumarins areanother fluorescent dyes involving in the fluorescent probes construction, have beendisclosed by our laboratory and other research groups that its3-and7-pointsmodification can well regulate its intramolecular charge transfer (ICT). This papehave conjugated coumarin dyes with BODIPY dyes by a double carbon bonds, aseries of new dyes have been obtained. In this work, I known that the new series ofcoumarin-BODIPY conjugated compounds have easy tunable photophysic properties(due to its ICT,red emission at compound5, deep red at6,to near infrared at7),lager extinction coefficients,big Stoke shifts and relatively high fluorescencequantum yields. I think these new dyads will applied in chemistry, biology, andmedicine fields and the dyads design method will provide a way for other new dyesdevelopment.In Chapter III, this paper have described a compound Ratio-HPSSC based onthe tertrakis(4-hydroxyphenyl) porphyrin coumarin scaffold as a novel ratiometricfluorescent thiol probe. We kown the small molecular weight thiols such as cysteine,homocysteine, and glutathione play an important role in biological redox homeostasis,biocatalysis, met al binding, and post-translational modifications. However, theabnormal levels of thiols are also associated with many types of diseases. Therefore,it is of high interest to monitor the thiol levels in bio-systems. The majority of the existing fluorescent thiol probes are fluorescence intensity-based. By contrast, only afew of fluorescent thiol probes are based on ratiometric fluorescence measurement attwo wavelengths, which should provide a built-in correction for environmentaleffects. In this work, the key of the new ratiometric fluorescent probe Ratio-HPSSCinclude high sensitivity, high selectivity, a large change (I459/I658=60-foldenhancement) in the emission ratio, a low detection limit（0.73μmol/L） and alarge fluorescence dynamic range. Importantly, the novel ratiometric probe exhibiteda remarkable change in emission color from red to blue. This key feature allowsRatio-HPSSC to be employed for thiol detection by simple visual inspection.Furthermore, This pape have demonstrated that Ratio-HPSSC is suitable forratiometric fluorescence imaging of thiols in living cells. I believe that the newratiometric probe will find interesting applications in chemistry, biology, andmedicine.