Studies On The Fluorescent Sensors Based On Organic Molecules And Rare-earth Coordination Polymers

Due to their simple structure,convenient synthesis,fast response,simple operation,high sensitivity and selectivity,and real-time monitoring,fluorescent sensors are broadly applied to detect anions,cations,biomolecules,temperature,humidity and pressure,which play a pivotal role in physiological processes.Fluorescent sensors play an increasingly important role in life sciences,materials science,food science,environmental testing,biochemical sensing,bioimaging,immunoassay and medical diagnostics.Therefore,it is meaningful to design a fluorescent sensor with lower cost,wider application range and more versatile functions.Based on the research topic of fluorescence analysis,we have synthesized a series of organic molecules and rare earth coordination polymer fluorescent sensors for the detection of reactive sulfur species,ions and nitroaromatic explosives.Moreover,based on the reported organic molecules and rare earth coordination polymer fluorescent sensors,we have made a certain degree of structural optimization to make them have better performance.The full text is mainly divided into seven parts:1.The classification,design principle and mechanism of host-guest recognition of fluorescent sensors are briefly introduced.The current research progress of fluorescent sensors based on organic molecules and rare earth coordination polymers is emphatically summarized.2.A H₂S fluorescent probe was designed and synthesized based on coumarin fluorophore of Micheal addition mechanism.The detection limit of the probe towards H₂S is as low as 5×10^-8 M,and the detection process of the probe towards H₂S can be completed in a short time?<60 s?.Furthermore,the probe has been successfully applied to detect H₂S in living cells.3.We have successfully synthesized a dual-site and dual-excite fluorescent probe to detect thiol based on coumarin fluorophore.When excited at 470 nm,the probe only has a significant fluorescence signal change towards ArSH;when excited at 453nm,the probe has different fluorescence signal changes towards Cys,Hcy and ArSH,which enables the discriminate detection of Cys,Hcy and ArSH.Furthermore,the probe has been successfully applied to discriminatively detect and image Cys,Hcy and ArSH in living cells.4.Based on the work of previous chapter,we designed two hydrosoluble triple-site and triple-excitation alternative NIR fluorescent probes 1 and 2 based on chlorinated coumarin-hemicyanine,which can be used for distinguishing recognition of Cys,Hcy and GSH in PBS.Across different excitation,probes exhibited different fluorescence responses towards Cys,Hcy and GSH,respectively.Furthermore,probes were successfully applied to simultaneously image exogenous and endogenous Cys,Hcy and GSH in living cells through three different emission channels.5.A new lanthanide coordination polymer?Eu-CP?was successfully assembled through a solvothermal method.The fluorescent tests indicate that Eu-CP can be used as a fluorescent probe to detect Fe³⁺/Fe²⁺,Cr₂O₇^2-,and NAEs.Interestingly,Eu-CP can not only effectually distinguish CrO₄^2-and Cr₂O₇^2-,but also sensitively identify the above-mentioned NAEs,including NB,1,3-DNB,4-NT,2,4-DNT,TNT,and PA.More importantly,Eu-CP can be reused at least five times in the detection process of Cr₂O₇^2-and NAEs.6.Based on the work of previous chapter,a new Tb-CP was successfully fabricated by solvothermal reaction.Fluorescence spectra show that Tb-CP can selectively detect Fe³⁺,Cr^VI anions,and PA in aqueous solution.Furthermore,the detection limits of Tb-CP towards Fe³⁺,Cr^VI,and PA are as low as 50,100 and 50 nM,respectively.More significantly,Tb-CP can be easily recycled at least 5 times in the detection process of CrO₄^2-/Cr₂O₇^2-and PA.7.The summary and prospect,including the conclusion of experimental results,the analysis of innovations and deficiencies of the fluorescent probe reported in this paper,and the prospect of fluorescent probes based on organic molecules and rare earth coordination polymer.