Lanthanide Coordination Polymers As Ratiometric Fluorescent Sensors:Design And Sensing

In recent years,the fluorescence analysis has attracted great attention due to the high selectivity,good selectivity,facile synthesis,fast response and low cost.As ideal optical materials,lanthanide coordination polymers?Ln CPs?possess many excellent properties,including high quantum yield,large stokes shift,long luminescence lifetime and good biocompatibility,which make Ln CPs widely used in many fields.In this thesis,a series of novel fluorescence sensors were established based on the Ln CPs.The formed fluorescence sensors were successfully applied to detect metal ions and biological small molecules.The main work will be written in details as follows:1.Carbon dots doped lanthanide coordination polymers as universal fluorescent platform for ratio sensing the targetHerein,the AMP-Tb Ln CPs were prepared by self-assembly of AMP and Tb³⁺.Carbon dots?CDs?were encapsulated in polymers as guest materials,and the obtained CDs@AMP-Tb only emitted the characterized fluorescence of CDs,the lanthanide coordination polymer by introducing suitable antenna ligand.Upon the target addition,the fluorescence of Tb³⁺decreased,while the fluorescence of CDs remained constant.The possible mechanism was the target coordinated with antenna ligand,and thus inhibited its antenna effect.The obtained fluorescent probe cysteine?Cys?.Based on this phenomenon,a universal ratio fluorescence sensor was constructed.2.Carbon dots doped lanthanide coordination polymers as dual-function fluorescentA novel kind of carbon dots?CDs?doped lanthanide coordination polymersHerein,blue-light emitting CDs,as the Fe³⁺-sensitive probe,were incorporated into the Fe²⁺-sensitive Ln CPs through the self-adaptive ability.The obtained composite probe can be efficiently excited at a single wavelength and shows good separate sensitive probe was quenched,while another probe maintained constant serving as an respectively.The rational design strategy for multi-analyte assay,and the facile preparation and operation make it possible for simultaneous monitoring two or more relevant analytes in one system.Furthermore,by virtue of the reduction capability of ratio-metric determination of AA as well.3.Dual luminescent lanthanide coordination polymers for ratiometric sensing andA new fluorescence ratiometric method for Hg²⁺assay based on the dual-ligand fluorescent probe GMP-Tb-luminol coordination polymers?CPs?was constructed.The GMP-Tb-luminol was composed of Tb³⁺as the center metal ions and ligand of GMP together with the cofactor luminol ligands as the bridging ligands.The probe could be excited at the same wavelength and reveal characteristic luminescence of Tb³⁺and luminol with spectrally distinguishable emission peaks.The addition of constructed by measuring the ratio of fluorescence intensity of luminol at 430 nm proposed method had been successfully used for the determination of Hg²⁺in tap water.