Construction And Application Of Fluorescence Enhanced Lanthanide Coordination Polymer Probes

In recent years,lanthanide coordination polymers have aroused unprecedented attention in sensing due to the large Stokes shift,longer fluorescence lifetimes and sharp emission peaks.Fluorescent Enhanced lanthanide coordination polymers probes got more and more attention.In the study of this paper,Four kinds of fluorescence enhanced lanthanide coordination polymers probes were designed and constructed and specifically detected amyloid,citrate,guanylate and zinc ions,respectively.Main research content:?1?This work presents a novel strategy for the construction of LCP for sensitively turn-on fluorescent sensing of A?_1-40.Herein,using Tb³⁺as the luminescence center,1,3,5-benzenetricarboxylate?BTC?as building block and Cu²⁺as the signal modulator as well as a recognition unit,A novel and effective fluorescent sensor?Cu-BTC/Tb?for amyloid?-peptide?A??monomer was designed.Specifically,Cu-BTC/Tb is almost non-emissive due to the quenching effect of Cu²⁺,exhilaratingly,the presence of A?_1-40 triggered a significant emission enhancement of Cu-BTC/Tb assay due to the high binding affinity of A?_1-40 for Cu²⁺and the subsequent suppression of the quenching effect.In the assay,this sensor shows high sensitivity with detection limit of 0.3 nM.Due to its capability to eliminate auto-fluorescence,Cu-BTC/Tb was also applied to the time-gated detection of A?_1–40–40 in human plasma with promising results.?2?Tb-GMP based biosensor for citrate?Cit?was designed by utilizing terbium ion(Tb³⁺)as luminescence center,guanosine monophosphate?GMP?as organic ligand.Tb-GMP is weak luminescent,interestingly,after the addition of Cit,a 6.5 times fluorescence enhancement was observed owing to the removal of coordinated water molecules by Cit and an intramolecular energy transfer from GMP to Tb³⁺.In this assay,the fluorescent intensity of Tb-GMP displayed a good linear response to Cit concentrations in the range of 4-300?M.Due to its capability of eliminating autofluorescence,also,Tb-GMP was applied for detection of Cit in urine with promising results.?3?A kind of novel lanthanide coordiantion polymer of Tb-Cit with fluorescence sensing function for guanosine monophosphate?GMP?was prepared by the self-assembly of citrate?Cit?and lanthanide ions.The sensor of Tb-Cit displayed weak luminescence.After the introduce of GMP and formation of Tb-Cit/GMP ternary LCP,the luminescence of the Tb-Cit was enhanced 15 times and exhibited excellent selectivity and high sensitivity to GMP with detection limit of 0.15?M.The sensor of Tb-Cit possesses long luminescence lifetime up to millisecond,which is predominant for applying in detecting GMP in complicated matrix of infant formulas and ham by time-resolved fluorimetry.?4?A kind of LCP assay for Zn²⁺was prepared.The LCP were composed by Eu³⁺and guanosine-5?-monophosphate?GMP?,which are denoted as Eu-GMP.Eu-GMP are almost non-luminescent,interestingly,significant fluorescence enhancement is observed owing to a more efficient energy transfer from GMP to Eu³⁺induced by the joining of Zn²⁺.The fluorescence intensity of Eu-GMP at 614 nm showed a linear relationship with the concentration of Zn²⁺from 4?M to 240?M.Due to possessing long fluorescence,for application in serum Zn²⁺determination,Eu-GMP showed preeminent achievement.