Design And Synthesis Of Novel Fluorescent Probes And Their Application

Developing sensor systems that allow for the effective and rapid detection of analytes constitutes a major focus in food safe and biological chemistry.A specific subset of sensors,fluorescent probes have attracted attention for both analytical sensing and optical imaging because of their high sensitivity,fast response time,and technical simplicity.Ideally,fluorescence sensing systems are able to provide a reliable fluorescent response under the conditions of analysis associated with the targeted analyte,be those chemical,environmental,or biological.In this thesis,three novel probes for H2 S,Cys/GSH and sulfite were designed and synthesized.The paper includes five chapters:The first chapter is a literature review,which introduces the classification,factors and design principles of biological fluorescent probes.The second chaper is focus on the designed and synthesized of a novel probe for rapid and selective detection of hydrogen sulfide in living cells.In this part,we have successfully developed a novel fluorescent probe for hydrogen sulfide base on indole-BODIPY platform.The probe displayed a remarkable fluorescence "turn on" response(200-folds enhancement)to H2 S,which was triggered by cleavage of the 2,4-dinitrobenzenesulfonyl(DNBS)unit by the interaction with hydrogen sulfide.This probe has some advantages including fast response(t1/2 = 2.5 min),long emission wavelength(?em = 635 nm),good selectivity and low detection limit(0.02 ?M).Cell staining results indicated that the probe had good permeability,and could visualize hydrogen sulfide in the living.The third chaper is focus on the designed and synthesized of a smart fluorescent probe for simultaneous detection of GSH and Cys in human plasma and cells.In this part,we have successfully developed a novel fluorescent probe based on the conjugate of indole-BODIPY platform and 7-nitrobenzofurazan.This probe displays fast and dual-emission response to Cys through nucleophilic aromatic substitution-rearrangement,while it only shows fluorescence "turn-on" response to GSH at a single emission band,which can be used to discriminate Cys from GSH.This probe has some advantages including long emission wavelength(?em = 635 nm),good selectivity,and capability for simultaneous detection of Cys and GSH.Therefore,the probe has a great potential application in monitoring the dynamics and levels of GSH/Cys in biological systems.This study not only develop a fluorescent probe that can sense GSH and Cys simultaneously,but also provide a strategy for multicomponent analysis in the living systems.The forth part is focus on the designed and synthesized of a ratiometric fluorescent probe for detection of sulfites.In this part,we have designed and synthesized a ratiometric fluorescent probe for the ratiometric detection of SO32-based on coumarn.This probe exhibits high selectivity and sensitivity towards SO32-even in the presence of a high concentration of H2 S.In addition,this probe has fast response time(within 60s)and low detection limit(20 nM).The probe was also successfully applied to detect sulfite in real samples with good recovey.The fifth chapter is the conclution of this thesis,which summarizes the experimental results.