Synthesis And Application Of Europium(Ⅲ) Complexes Fluorescence Probes

Time-resolved fluorescence (TRF) bioassay technique based on long-lived fluorescence of lanthanide probes is an ultrasenstive bioanalytical method, and has been widely used in clinical diagnostics and biotechnology. This thesis aims to design and synthesize new europium luminescence chelates for highly sensitive TRF bioassays.A novel naphthyl-substituted Europium(III) complex,4'-(1-naphthyl)-2,2',6',2"-terpyridine-6,6"-diyl]bis(methylenenitrilo) tetrakis (acetate)-Eu3+(NTTA-Eu3+), was designed and synthesized. The complex is highly water-soluble, and has high molar extinction coefficients and luminescence quantum yields (0.152), large Stokes shift (over 280 nm), long fluorescence lifetime (1.30 ms) and a high detection limit (2.60×10-11 mol/L). These results suggest that NTTA-Eu3+could be used for highly sensitive time-resolved luminescence bioassays as a luminescence probe. In addition, the effect of eleven kinds of metal ions on the fluorescence intensity was investigated. The result shows that only Cu2+strongly quenched the fluorescence of NTTA-Eu3+. In the concentration range of 3.0×10-6～3.0×10-5 mol/L, the luminescence intensity of NTTA-Eu3+shows a linear response towards Cu2+, and can be express as log(ΔF/F)= 7.4695+1.56551og[Cu2+] (r=0.9949).A new Eu3+chelate:4'-(3,4-diaminophenoxyl)-2,2',6',2"-terpyridine-6,6"-diyl] bis (methylenenitrilo) tetrakis (acetate)-Eu3+(DAPTTA), was designed and synthesized as a time-resolved fluorescence probe for the detection of NO. The synthetic intermediates and final product were characterized by using nuclear magnetic resonance and mass spectrometry. The result indicates the synthetic route is feasible. Further study on NO detection is in progress.