| Fluorescent probe has the advantages of being very sensitive,"on-off" switch ability, rapid, safe, remote sensing by using optical fibres and observation in situ et al. It has been widely used in determining ion concentrations in cell, DNA sequencing and immunoassay. Owing to the large molar extinction coefficient, high stability against light and the high fluorescence quantum yield, the rhodamine framework is an ideal mode for constructing OFF-ON fluorescent and chromophoric chemosensors because of its particular photophysics and photochemistry properties.In this dissertation, fifteen rhodamine B derivatives were designed and synthesized, including nine intermediate products. The target compounds were successfully characterized by HRMS, IR,1H NMR and13C NMR.The sensoring properties of target compounds (L1-L6) for metal ions were firstly studied by UV absorption and fluorescence spectroscopy, and the conditions for selectively detecting metal ion were investigated. Because of the strong thiophilic function of Hg2+, rhodamine B thioamides derivatives (L1, L2) suggested high selectivity for Hg2+over other interference metal ions. Rhodamine B hydrazide compounds (L3, L4) exhibited a rapid and sensitive upon coordination to Cu2+, and the recognition mechanism were fluorescence enhancement. The compounds (L5, L6) showed high affinity to Fe3+ion. Furthermore, this paper investigates the stoichiometric, competition experiments of metal ion and limits of detection of the ions upon probes detecting metal ion.Through the agarose gel electrophoresis, preliminary study on the cleavage activity for these ligands (L1-L6) in the presence of metal ions on the pUC19DNA. This paper thinks from buffer, pH value, concentration and reaction time to select the optimum condition on the cleavage of pUC19DNA by complexes. Moreover, we have investigated the reaction mechanism on the cleavage DNA. |
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