Design,Synthesis And Application Of New Europium(Ⅲ) Complex-based Luminescent Probes For The Specific Detection Of Peroxynitrite

In time-gated luminescence bioassay technique,lanthanide complex-based molecular luminescent probes have been widely used in biological analysis and clinical medical due to its advantages of high sensitivity and low background fluorescence interference.At the same time,peroxynitrite（ONOO^-）,as a strong oxidizing cytotoxic species,can cause serious damage to the organism.In this academic dissertation,we synthesized two novel europium complex-based luminescent probes,and established new methods for the time-gated luminescence detection of peroxynitrite in aqueous media and living cells.In the structure design of the probes,by introducing 2,4-dimethoxyphenyl into?-diketone ligand as a ONOO^-recognition group,we synthesized two?-diketonate-europium（III）complex-based time-gated luminescence probes,and established the time-gated luminescence detection methods for the determination of ONOO^-in aqueous media and the time-gate luminescence imaging methods for the detection of ONOO^-in living cells.To solve the above problems,this thesis focuses on the following contents:1.The synthesis and application of the ONOO^--responsive europium（III）complex-based luminescent probesA 2,4-dimethoxyphenyl-containing?-diketone ligand,1,1,1,2,2,3,3-hetafluoro-6-（2,4-dimethoxyphenyl）-4,6-hexanedione（HDPH）,was firstly designed and synthesized.Then the?-diketone ligand was coordinated with Eu³⁺and 2,2′,2′′-terpyridine（tpy）to form a new?-diketonate-europium（III）complex-based luminescent probe[Eu（HDPH）₃（tpy）].The probe is highly luminescent（?=25.58%）,and the luminescence intensity is 64-fold decreased after reacting with ONOO^-,indicating a high sensitivity for the detection of ONOO^-.Moreover,the interference experiments of other reactive oxygen species prove that the probe shows high selectivity for ONOO^-.The probe has been successfully used for the time-gated luminescence detection of ONOO^-in aqueous media and living cells.2.The synthesis and application of the ONOO^--responsive visible-light-excited europium（III）complex-based luminescent probeOn the basis of the study of the luminescent probe[Eu（HDPH）₃（tpy）],by replacing the ligand tpy by a visible-light-sensitized ligand 2-（N,N-diethylanilin-4-yl）-4,6-bis（3,5-dimethylpyrazol-l-yl）-l,3,5-triazine（DPBT）,we synthesized a visible-light-excited europium（III）complex-based luminescent probe[Eu（HDPH）₃（DPBT）].The maximum excitation wavelength of the probe shifts to 400 nm,and the excitation window extends from ultraviolet to visible light region up to 460 nm.The probe[Eu（HDPH）₃（DPBT）]has been successfully used for the time-gated luminescence imaging detection of ONOO^-in living cells.Moreover,the photostability results of the probe-loaded cells demonstrate that the visible-light excitation is more favorable for the maintenance of the photostability of the probe compared to the UV excitation.