The Investigation Of Fluorescent Biosensor For Detecting Thiols Based On Coumarin

Among the numerous fluorophores,coumarin has many advantages as fluorescent probe,and biothiols have been proved to be associated with many diseases.Therefore,10 small-molecule fluorescent probes based on coumarin were designed to detect thiol in vivo,and corresponding measurement and bio-imaging experiment were performed on sensors with excellent properties.The work is divided into four parts:1.A brief introduction of the research status and development trend of the specific detection of thiols based on coumarin-based small molecule fluorescent probes.2.A series of fluorescence sensors were prepared using simple monocoumarins.Since the coumarin molecule is small,these fluorescent probes have very good water solubility and cell membrane permeability.For example,probe C1 can enter and image in Hek-293 a cells within one minute,and can also perform fluorescence imaging on plant cells.In view of the good biological application prospects of this series of probes,the probe C2 was used to achieve whole-body staining of mice and to observe the main organs,good results was also obtained.Due to the ease of synthesis and the simple structure,such small-molecule fluorescent probes are of potential commercial value.3.In order to overcome the short excitation and emission wavelength of monocoumarins,V-type dicoumarin with longer excitation and emission wavelength was prepared.The fluorophore has emission above 500 nm and two-photon excitation properties,which are very favorable properties for biological applications.Therefore,five bio-fluorescence sensors were designed to detect thiols based on the newly developed V-type dicoumarin.This is the first time that the dicoumarin structure has been applied to fluorescent probes and it has been proved to have two-photon properties.Compared to monocoumarins,which do not have the two-photon property,dicoumarins enable fluorescence imaging of biological samples having a certain thickness.The aromatic diethylamino group also has a lysosomal targeting function,which provides great convenience for the design of targeted fluorescent probes.4.A link-anthocyanin structure similar to the coumarin structure was prepared by a simple synthesis method,and the fluorophore has emission at 620 nm.This structure has a significant two-photon property,and since it exists in the form of salt,it has excellent water solubility.Since time is limited,only one fluorescence sensor C10 was prepared based on link-anthocyanin.After preliminary studies,C10 was found can accumulate in the RNA-enriched nucleolus and lysosomes due to its pyrylium structure.