Study On Synthesis Of Europium Complex-based Molecular And Nano Fluorescent Probes And Their Selective Detections For Peroxynitrite

Lanthanide complexes have attracted wide attention because of their advantages such as high fluorescence quantum yield,long fluorescence lifetime,large Stokes shift,wide excitation spectrum,and narrow emission spectrum.Meanwhile,the lanthanide molecular probes have various components and ligand molecules,and the structures and functional groups of nanoprobes can be adjusted.Therefore,more and more researchers are focusing on the application of lanthanide complex-based probes in the fields of heavy metal ions and biological detection.There are many small molecules in the organism,and the increase of ONOO-content may induce various diseases,such as cardiovascular and metabolic diseases,shock,arteriosclerosis,neurodegenerative diseases,cancer,etc.Therefore,europium???complex-based time-gated fluorescent molecular probe and nanoprobe were designed and synthesized for the detection of ONOO-,and cell imaging measurements using these two probes were performed.The two probes designed and synthesized in this paper are as follows:1.First,a novel europium???complex-based time-gated fluorescent probe [Eu?HDPH?₃?Phen-N?] was designed and synthesized.The ?-diketone ligand 1,1,1,2,2,3,3-heptafluoro-6-?2,4-dimethoxyphenyl?-4,6-hexanedione?HDPH?of the probe contained ONOO--specific capture group m-dimethoxyphenyl.The other ligand is 5-amino-1,10-phenanthroline?Phen-N?.The two ligands were coordinated with Eu³⁺ to form the ?-diketonate europium???complex-based fluorescent probe.The maximum excitation wavelength of this probe is 360 nm.After reacting with ONOO-,the luminescence of the probe is quenched,resulting in a 36-fold luminescence decrease.The probe shows high detection sensitivity and selectivity to ONOO-.On the basis of the experimental results in aqueous medium,the probe was further applied for the time-gated fluorescence imaging detection of ONOO-in living cells.2.On the basis of 1,Phen-N was covalently bonded with 3-?triethoxysilyl?propyl isocyanate to form Phen-Si.Then Phen-Si was coordinated with Eu³⁺ and the ?-diketone ligand HDPH to make a precursor.Finally,the precursor was further used for preparing the Si O2 nanoparticles by the W/O reverse microemulsion method,which could specifically detect ONOO-.The nanoprobe has a uniform particle size and is more stable in optical properties than the molecular probe in 1.In aqueous medium,the maximum excitation wavelength is 360 nm.After reacting with ONOO-,the luminescence of the nanoprobe is quenched,resulting in a 22-fold luminescence decrease.The nanoprobe was used for the time-gated fluorescence detection of ONOO-in living cells.