Synthesis And Application Of The Fluorescent Probes For In The Environment Copper(Ⅱ) And Sulfide Ions Detection

Lanthanide complex-based luminescent probes have shown great utilities in vari-ous biological and environmental assays with luminescent detection mode to eliminate background noises and improve the sensitivity.However,the technology applied in the detection of harmful further,the key to further application to the detection of harmful components in the environment is to develop a new lanthanide complex luminescence probe with specific recognition and luminescence response performance.In this work,by conjugating di（2-picolyl）amine（DPA）with a tetradentate betadiketone 1,2-bis[4’-（1",1",1",2",2"-pentafluoro-3",5"-pentanedion-5"-yl）benzyl]-4-chlorosulfobenzene（BPPBCB）,a novel dual-functional ligand that can coordinate to Eu³⁺ for responding to Cu²⁺ and S^2-ions in environmental samples,DPA-BPPBCB,has been designed and synthesized.The beta-diketone moiety of DPA-BPPBCB can form a strongly luminescent conjugate with Eu³⁺.The Job’s plotting analysis indicated that the coordination numbers of DPA-BPPBCB to Eu³⁺ were 2,meanwhile the coordination complex was[（DPA-BPPBCB）₂Eu]^-.The influence of the surfactants and other factors on the luminescence intensity of the DPA-BPPBCB-Eu³⁺ indicted the typical excitation peak at 328 nm and a main emission peak at 607nm in 50inmol/L borate buffer of pH 7.4 containing 0.1%CTAB（Bromide hexadecyl trimethylamine）,which the lifetime of the Eu³⁺ emission at 607 nm was 536μs,were determined.The effects of different metal ions and anions,different concentrations of Cu²⁺ and S^2- as well as several different copper complexes on the luminescence intensity of DPA-BPPBCB-Eu³⁺ were investigated.Upon reaction with Cu²⁺,accompanied by the formation of heterobimetallic complex Cu²⁺-DPA-BPPBCB-Eu³⁺,the Eu³⁺luminescence was quenched.While in the presence of S2-,owing to the high affinity of S2-to Cu²⁺,stable CuS was formed,to restore the luminescence of the Eu³⁺ complex.Therefore,the unique "on-off-on" luminescence response of the Eu³⁺ complex can be detected with luminescence mode of Cu²⁺ and S^2- ions in environmental samples.The luminescence quenching properties of the DPA-BPPBCB-Eu³⁺ conjugate to Copper ion in several complex(Cupric Citrate,Pyridine-Cu²⁺.2,2’-Bipyridyl-Cu²⁺,1,10-Phenemthrdine-Cu²⁺)were studied.The result demonstrated the DPA-BPPBCB-Eu³⁺ can be used in the detection of copper ion in complex.The fluorescent imaging of[（DPA-BPPBCB）₂Eu³⁺]used in Daphnia magna,which has normal metabolism in its body and does not produce toxic effect.Therefore,there was a great possibility for fluorescence detection of the complex used in biological body.