Zn(Ⅱ)、Cd(Ⅱ)、Eu(Ⅲ)-MOFs Used For Fluorescence Detections Of The Biomarkers In The Simulated Human Urine And The Inorganic Cations And Anions In The Environment

Metal-organic Frameworks（MOFs）are a new kind of crystalline multifunctional materials which combine inorganic and organic components by self-assembly.Based on the diversity of structures,MOFs exhibit broad application prospects in the fields of adsorption and separation,biomedicine,magnetism,chemical sensing and so on.In this thesis,three Cd/Zn-MOFs and two Eu-MOFs were synthesized based on pyridinyl-tetrazolate ligand 4-（tetrazol-5-yl）phenyl-4,2’:6’,4’’-terpyridine and aromatic polycarboxylic acid ligand 2-（2-nitro-4-carboxylphenyl）terephthalic acid via solvothermal method.The synthesis,structure and fluorescence sensing properties of these five MOFs were studied in detail.This thesis is mainly divided into the following five parts:The first part is the introduction,which mainly introduces the general situation of MOFs and their application in fluorescence sensing,and puts forward the basis of topic selection and research ideas of this thesis.In the second part,three new Cd/Zn-MOFs were synthesized by self-assembly using transition metal ions Cd²⁺and Zn²⁺and pyridinyl-tetrazolate ligand 4-（tetrazol-5-yl）phenyl-4,2’:6’,4’’-terpyridine under solvothermal conditions,presenting two-dimensional double-layered honeycomb structures（Cd-MOF-1 and Zn-MOF-2）and a three-dimensional structure（Cd-MOF-3）,respectively.These three Cd/Zn-MOFs can emit bright blue fluorescence,and can be used as fluorescence sensors for qualitative and quantitative detection of the biomarker hippuric acid（HA）（the metabolite of toluene in the human body）in the simulated human urine.The detection has the characteristics of rapid response,recoverability,high sensitivity,high selectivity,low detection limit and so on.In addition,the fluorescence quenching mechanism for hippuric acid of the three MOFs can mainly be ascribed to the fluorescence resonance energy transfer（FRET）.In the third part,a novel three-dimensional Eu-MOF-4 was successfully synthesized using lanthanide metal ion Eu³⁺and aromatic polycarboxylic acid ligand2-（2-nitro-4-carboxylphenyl）terephthalic acid under solvothermal condition.The fluorescence explorations indicate that Eu-MOF-4 can be used as a fluorescence sensor for qualitative and quantitative detection of the biomarker p-aminophenol（PAP）（the metabolite of aniline in the human body）in the simulated human urine and Mn O₄^-,Cr O₄^2-and Cr₂O₇^2-ions in aqueous solution.The detection of Eu-MOF-4 has the advantages of recycling,high sensitivity,high selectivity and so on.More significantly,Eu-MOF-4 is the first example of as a multi-responsive luminescence sensor for the detections of the biomarker PAP,Mn O₄^-,Cr O₄^2-and Cr₂O₇^2-ions simultaneously in water system.In the fourth part,a novel three-dimensional Eu-MOF-5 was designed and synthesized using lanthanide metal ion Eu³⁺and terephthalic acid by solvothermal method.To the best of our knowledge,Eu-MOF-5 is the first multi-response fluorescence sensor that can efficiently detect the biomarker 1-naphthol（the metabolite of the pesticide carbene（1-naphthyl-N-methylcarbamate）in the human body）in the simulated human urine and Fe³⁺and Mn O₄^-ions in aqueous solution.More importantly,the sensor can be regenerated easily and quickly,exhibiting remarkable recyclability for the detection of 1-naphthol,Fe³⁺ions and Mn O₄^-ions.Eu-MOF-5 as a promising fluorescence sensor has the potential applications in biological and environmental areas.The fifth part is the conclusion,which mainly summarizes the research contents of the crystal structure and fluorescence sensing of the five MOFs in the previous chapters,and further draws the relevant conclusions.