Design,Synthesis And Fluorescent Sensing Properties Of Tb³⁺-based Composite Nanomaterials

Fluorescent chemical sensing is a detection method which recognizes the difference in fluorescent signals of the specific molecules and environment with fluorescent materials.Among many of the fluorescent dye molecules,lanthanide complexes have attracted more and more attention owing to the characters of narrow emission spectrum,long lifetime and large Stokes shift.However,the lanthanide complexes still have some defects used in water,such as photobleaching,poor water solubility and stability.In order to give full play to the properties of Ln³⁺and make up for the deficiency,lanthanide composite nanomaterials have been extensively studied.Thereinto,the lanthanide composite nanomaterials based on supramolecular assembly have certain superiority in stimulus responsiveness and fluorescent sensing sensitivity.But there are limitations on the study of the relation between the behavior of supramolecular assembly and lanthanide fluorescent sensing.Therefore,based on the strategy of supramolecular assembly,the article for one thing,studied the functional application and the relationship of lanthanide composite nanomaterials fluorescent sensing with non-covalent interaction under different temperature,clearing about the role of non-covalent interaction in materials assembly and signals response,at the same time,exploring the feature of Ln³⁺fluorescent temperature sensing,providing new thoughts for its application in temperature response.For another,nano-microsphere was synthesized by assembly for the specific response of anion recognition.Combined with Ln³⁺fluorescent sensing,the detection method was optimized to provide a new strategy for the quantitative analysis of ion concentration.This paper is mainly divided into the following four parts:Chapter 1:Briefly describes the principles,applications,performance parameters of fluorescent chemical sensing and the principles,applications,advantages of lanthanide fluorescent sensing.Chapter 2:In order to study the relationship of lanthanide composite nanomaterials and non-covalent interaction,the experiment designed and synthesized a new amphiphilic ligand,coordinated with Tb³⁺,and then introduced the antenna ligand,forming the Tb³⁺complexes,making its self-assembly in aqueous solution.In order to reflect the effect of non-covalent interaction,further analyzing the difference of Tb³⁺fluorescent signals and assembly morphologies change under different temperature,a control group was set to explore the effect of different antenna ligands'temperature-induced?-?stacking on Tb³⁺fluorescent temperature sensing and its functional application.The result showed that the non-covalent interaction played an important role in real-time temperature monitored by the fluorescent intensity and lifetime of Tb³⁺,and fed back by the fluorescent sensing mode.This study is expected to provide new mind for in-depth exploration of the relationship between non-covalent interaction and lanthanide fluorescent sensing.Chapter 3:In order to study the application of lanthanide composite nanomaterials in the field of ion detection and the feasibility of ion concentration quantitative analysis by fluorescent intensity and lifetime,the experiment designed the nano-microspheres through the method of“one pot”to assembled Tb³⁺and organic molecular,and synthesized the specific responsive nano-microspheres by ligand modification.Then,the experiment conducted the nano-microsphere fluorescent ion sensing research,explored the specificity of anion identification and the feasibility of Tb³⁺fluorescent intensity and lifetime in ion detection as well as the reason of specific recognition.The result showed that the microsphere with the property of selective recognition Cr₂O₇^2-possessed of good response in quantitative analysis experiments of fluorescent intensity and lifetime.At the same time,the specific recognition is due to the fact that Cr₂O₇^2-obstructs the light absorbed by the microspheres,and might have influenced the transition of excited Tb³⁺,quenching the fluorescence and shortening the lifetime of Tb³⁺.This detection mode improves the accuracy of ion detection and broadens the functional application of lanthanide fluorescent sensing.Chapter 4:The research contents of this paper are summarized and prospected:the lanthanide composite nanomaterials prepared in this paper were analyzed,and the development of self-assembly lanthanide composite nanomaterials is prospected.