Synthesis And Spectral Properties Evaluation Of 7-(Diethylamino) Coumarin Scaffold-based Fluorescent Probe

The fluorescent probe can react with the detected substance to generate new molecules and change the fluorescence properties to achieve the purpose of detecting the target substance.Coumarin compounds are a kind of natural compounds that widely found.Coumarin fluorophores have the advantages of good optical properties,many modification sites and good photostability.In this paper,We using 7-（diethylamino）coumarin as fluorophore groupthree synthesized three fluorescent probes.The probes were used to detect three kinds of substances,namely,peroxy nitroso,hydrogen sulfide and hypochlorous acid.As the highly active reactive oxygen/active nitrogen in human body,the abnormal levels of peroxynitrosine may lead to inflammation,neurodegenerative diseases,cancer and so on.As an important active sulfur,hydrogen sulfide is an gas signaling of human body and participates in various physiological regulation activities,such as regulating blood pressure,myocardial contraction and endocrine system,etc.Abnormal hydrogen sulfide may lead to Alzheimer’s disease,hypertension,Down syndrome,etc.Hypochlorous acid is a reactive oxygen species.Abnormal levels of hypochlorous acid can cause a series of diseases that harm human health（cancer,neurodegenerative diseases）and reduce people’s quality of life（atherosclerosis,arthritis）.Therefore,the detection of these three active substances make a big diffience..In chapter 1,the research progress of small molecule fluorescent probes with three kinds of objects,namely,peroxide nitroso,hydrogen sulfide and hypochlorous acid,is summarized.In chapter 2,DBP probe was synthesized by using 7-（diethylamino）coumarin as fluorophore and phenylborate pincinol ester as reaction group.Probe DBP itself has light yellow fluorescence.After adding peroxy nitroso anion,borate ester group is oxidized and broken,hydroxyl group is exposed,and green fluorescence is produced.The probe DBP can specifically identify peroxynitrosite anions,and has the advantages of fast reaction speed,good linear relationship,good p H stability,and naked eye observation.In chapter 3,the probe ZHC was synthesized with 7-（diethylamino）coumarin as fluorophore and azide group as reaction site.The probe ZHC itself has blue fluorescence.After S^2-ion is added,the azide group is reduced to amino group,resulting in fluorescence change and yellow fluorescence,which achieves the detection purpose.Probe ZHC has the advantages of good optical performance,high sensitivity and specific recognition of S^2-.The linear range is 0-20μM,with a minimum detection limit of 0.98μM.In chapter 4,the probe DTMM was designed and synthesized based on the mechanism of malononitrile protecting the aldehyde group with 7-（diethylamino）coumarin as fluorophore.The probe DTMM itself has weak fluorescence.After hypochlorite ion is added,it reacts with C=C of malononitrile linked to the thiophene ring,disconnects C=C bond,and emits strong fluorescence to achieve the purpose of detection.The probe has a good linear range（0-14μM）and specific recognition of HCl O,with a minimum detection limit of 40 n M.