Design,Synthesis And Application Of Europium(Ⅲ) Complex-based Luminescent Probes

The time-gated luminescence analysis technique based on lanthanide probe has been widely used in environmental analysis and biotechnology.In recent years,the time-gated luminescence analysis technique is further applied for the detection of harmful components in the environment and biological systems.In this dissertation,three new europium（III）complex-based fluorescent probes were designed,synthesized and used for the establishment of new time-gated luminescence detection methods for Cu²⁺,S^2-,and ¹O₂ in aqueous media and living cells.The contents of this thesis are divided into the following three aspects:BycovalentlybindingtheCu²⁺-recognitiongroup-containing N,N-bis（2-pyridylmethyl）ethanediamine（BPED）to a tetradentateβ-diketone ligand4,4’-bis（1”,1”,1”,2”,2”,3”,3”-heptafluoro-4”,6”-hexanedione-6”-yl）chlorosulfo-o-terphenyl（BHHCT）,a strongly fluorescent?-diketonate-europium（III）complex-based probe,Eu³⁺-BHHCT-BPED,has been designed and synthesized.The probe exhibits an excellent chemical stability,high luminescence quantum yield（57.6%）and wide pH range.After reacting with Cu²⁺,the fluorescence of the probe was efficiently quenched.However,due to the strong affinity between Cu²⁺and S^2-,the addition of S^2-to the solution restored the fluorescence of the quenched probe.The fluorescent probe shows high sensitivity and selectivity for the detection of Cu²⁺and S^2-,which has been successfully applied for the detection of Cu²⁺and H₂S in aqueous media and living cells.On the basis of the study of the fluorescent probe Eu³⁺-BHHCT-BPED,a visible-light-excited europium（III）complex-based fluorescent probes BPED-BHHCT-Eu³⁺-BPT was firstly synthesized for the detection of Cu²⁺and S^2-by introducing a visible-light-sensitized ligand 2-（N,N-diethylanilin-4-yl-4,6-bis（pyrazol-1-yl）-1,3,5-triazine）（BPT）to Eu³⁺-BHHCT-BPED.The probe displays the same advantages as Eu³⁺-BHHCT-BPED.It is notable that the visible excitation light can reduce damage to the biological samples and photobleaching to the probe compared to the UV one.The highly sensitive time-gated luminescence imaging detection of Cu²⁺and S^2-in living cells has been accomplished by using this probe.A terpyridine derivative ligand 4’-（9-anthryl）-2,2’:6’,2”-terpyridine（ATPD）containing singlet oxygen（¹O₂）-recognition group of anthryl was firstly designed and synthesized.Then theligandwascoordinatedwithEu³⁺andaβ-diketoneligand5-（1’,1”-bis-phenyl-4’-yl）-1,1,1,2,2,3,3-heptafluoro-4,6-hexanedione（BHH）to form a novel¹O₂-responsive?-diketonate-europium（III）complex-basedfluorescentprobe Eu³⁺（BHH）₃（ATPD）.The probe itself is almost non-fluorescent.Upon its reaction with ¹O₂,a strongly fluorescent complex is produced with a 12-fold luminescence quantum yield enhancement.The probe exhibits wide pH range,and high sensitivity and selectivity for ¹O₂.