Design And Synthesis Of Fluorescent Probes Based On Novel Dyes

Fluorescent molecular probes refer to compounds that can interact with the analytic target and cause changes in their optical properties. Based on these change, the target analyte could be analyzed. The use of fluorescent molecular probes can not only improve the sensitivity of analysis, but the space and time resolution of the sample can be also greatly improved. Therefore, it has been a hotspot in the field of chemical research, and attracted extensive attention of researchers. In recent years, fluorescence imaging has become one of the most important means to monitor small molecules of biological processes in vivo, and excellent fluorescent probes have been proved to be the material basis to realize imaging analysis.In this thesis, novel xathene and cyanine dyes have been designed and prepared. Meanwhile, chemsensors and probes have been designed and investigated by using these fluorescent dyes as signaling fluorophores. In detail, we have carried out the following works:(1) We have developed a novel xanthene dye L from commercially available naphthalene-1, 4-diol and 2-(4-diethylamino-2-hydroxybenzoyl) benzoic acid. It exhibits a combination of desirable characteristics including(i) low molecular weight,(ii) water solubility,(iii) cell permeability,(iv) excellent biocompability, and(v) strong tolerance to p H. Meanwhile, the dye can be easily modified to chemosensors and bioprobes.(2) On the basis of above work, we synthesized compounds L1-L4. L2 can selectively recognise mercury ion in 25% ethanol aqueous solution, and L3 has good selectivity to the glutathione(GSH) in 50% ethanol HEPES solution, and its detection limit reached 10-8 M, and can be applied to detection of GSH in living cells.(3) We designed and synthesized dyes J1-J6. UV-vis and fluorescence spectrum show that compound J1-J6 have significant selectivity of DNA in 2 m M phosphate buffer solution. When J1 combined with DNA, its fluorescence enhanced; while J2-J6 combined with DNA, their fluorescence quenched. Hence J1-J6 can be served as good DNA binders; especially J1 can be used as a fluorescence probe in the detection of DNA.In conclusion, from the perspective of the molecular structure innovation, we have designed and synthesized a series of xanthene and hemicyenine fluorescent dyes, which are proposed to solve some problems in constructing fluorescence imaging probes.