Design And Synthesis Of Xanthene Fluorescent Dyes For Applications In Fluorescence Imaging

In this thesis,the different types of xanthene fluorescent dyes were designed and synthesized,and the photophysical properties of these dyes have been studied in detail.Moreover,one xanthene fluorescents dye was developed for the fluorescence detection of thiophenol.The main research works are as follows:First,a series of xanthene fluorescent dyes containing heterocycles,dense heterocycles and conjugated dense rings have been obtained.The molecular structure of dyes was confirmed by ~1H NMR and HRMS.The maximum absorption and emission wavelengths of dye RB-triphenylamine(D)is 664 nm and 795 nm,respectively.Then the optimal configurations of these dyes were calculated by density functional theory(DFT).The relationship between theoretical calculation results and experimental spectra data was discussed in detail.Furthermore,these dyes were used for fluorescence labeling imaging of MCF-7 cells,and the results showed that dyes of RB-triphenylamine(D),RB-thiophene(G),RB-pyrrole(H),RB-hdroxybenzene(L),RB-benzofuran(N),and RB-benzothiophene(O)has better labeling effect on MCF-7 cells.Among them,fluorescent dye RB-triphenylamine(D)has the ability of targeting cell mitochondria.Because thiophenol has strong toxicity,a near-infrared fluorescence probe RB-dinitrophen oxy-benzylidene(NOF)for thiophenol detection was synthetized,with xanthene as the fluo rescent group and 2,4-dinitrophenyl ether as the recognition unit.The probe has the adva ntages of large Stokes shifts,fast response,high sensitivity and good selectivity in respons e to thiophenol.Meanwhile,the probe NOF has been successfully applied to the quantitati ve recovery and detection of thiophenol in actual water samples.In addition,the probe N OF has good cell permeability and low toxicity,and can be used for intracellular thiophen ol fluorescence imaging.Finally,the probe NOF was applied to fluorescence imaging of t hiophenol in mice.