Syntheses And Fluorescence Sensing Properties Of Luminescent Matel Organic Frameworks Materials And Its Application In Fluorescence Detection

At present,the abuse of antibiotics and pesticides has become a serious problem facing human society.Antibiotics and pesticides enter the environment through various ways,which have a serious impact on the environment and human health at the same time.Previous studies have focused on how to remove antibiotics and pesticides from water environments.However,before the application of advanced removal technologies,the detection of antibiotics and pesticides in wastewater and the detection of antibiotics and pesticide residues after wastewater purification are also important issues.So how to solve these problems has become the focus of attention.To compare with traditional detection methods,fluorescence detection technology is more economical and simple.Finding the suitable fluorescent probe has also become the focus of research.As a new inorganic-organic hybrid material,luminescent metal-organic frameworks（MOFs）can combine the advantages of traditional inorganic or organic luminescent materials and break through the performance shortcomings of traditional traditional inorganic or organic luminescent materials.The use of luminescent MOFs as fluorescent probes for antibiotics detection has become a research direction of great concern.Researchers at home and abroad have also done some representative research work in this area,and we have done a lot of work on this basis.This paper is based on the previous work of the research group.A series of monometallic rare earth isomorphic complexes and bimetallic rare earth isomorphic complexes were synthesized by using 1-（1,3,4-triazolyl）-2,4,6-isophthalic acid（H₃tzbt）as the ligand and rare earth metal as the metal center,and the synthetic method is hydrothermal solvothermal method.Four Zn-MOFs with the same metal structure and different metal centers synthesized before the research group were selected,which were based on 3-（2-pyrazinyl）-5-（4-pyridyl）-1,2,4-triazolyl and Zn matel.The crystal structure,thermal stability and photoluminescence properties of the complexes were investigated.The properties of the complexes as fluorescent probes for detecting antibiotics and pesticides were explored.The factors affecting the fluorescence detection performance of rare earth complexes with the same structure and different metals and the factors affecting the fluorescence detection performance of transition complexes with different structures of the same metal were mainly explored,and the relevant laws were summarized.It provides some valuable information for the further study of fluorescence detection of antibiotics and pesticides.The main work of this paper is as follows:1)A series of isomorphic monometallic three-dimensional rare earth MOFs[Ln（tzbt）（H₂O）_n]_n（Ln=Eu（1）,Tb（2）,Ce（3）,Pr（4）,Nd（5）,Sm（6）,Gd（7）,Yb（8）,Dy（9）,Er（10）,Ho（11）,Lu（12）,Tm（13）,Y（14））were synthesized.Which were obtained based on ligand 1-（triazol-1-yl）-2,4,6-benzene tricarboxylic acid（H₃tzbt）.The basic characterization was carried out.The photoluminescence properties of four materials（1-Eu,2-Tb,6-Sm and 9-Dy）were measured.1-Eu and 2-Tb,which have good luminescence properties,were selected as antibiotics and pesticide probes for related tests.Both 1-Eu and 2-Tb can detect sulfadimidine（SMZ）in water with high sensitivity.The two materials have good anti-interference ability and circulation performance when they are used as fluorescent probes to recognize antibiotic.2)A series of isomorphic bimetallic three-dimensional rare earth MOFs[Eu_2/3Ln_1/3（tzbt）（H₂O）_n]_n（[Ln=Yb（15）,Dy（16）,Er（17）,Tm（18）,Pr（19）,Ho（20）,Nd（21）]）and[Tb_2/3Yb_1/3（tzbt）（H₂O）_n]_n（22）were synthesized by incorporating different kinds of rare earth metals into 1-Eu and 2-Tb,which was subjected to basic characterization and photoluminescence performance testing.The doping of rare earth metal Yb can improve the fluorescence effect of the materials.Two cases of double rare earth MOFs 15-Eu-Yb and 22-Tb-Yb with improved fluorescence effect after doping,were used as fluorescence probes and measured at four different excitation wavelengths（250 nm,270 nm,300 nm,respectively）.It was found through testing that the types of antibiotics detected by these double rare-earth MOFs 15-Eu-Yb and 22-Tb-Yb at different excitation wavelengths changed,indicating that the type of antibiotics can be changed by changing the excitation wavelength.3)A series of complex materials 23-26 with four different structures,which synthesized from the same ligand 4-Hpzpt and d¹⁰electron orbital metal Zinc were selected.These four materials can detect nitrofuran antibiotics in water with high sensitivity,good anti-interference ability and recycling performance.The factors affecting the detection of antibiotic properties of the same metal complexes with different structures were explored.4)Based on the work of monometallic rare earth MOFs and bimetallic rare earth MOFs as fluorescent probes for antibiotic detection,pesticide identification tests were carried out for two single rare earth MOF 1-Eu and 2-Tb with high sensitivity.It was found that 1-Eu and 2-Tb can detect thiamethoxazine（TMT）in water with high sensitivity,and have good anti-interference ability and circulation performance.After that,the properties of 15-Eu-Yb and 22-Tb-Yb for detecting pesticides under different excitation（250 and 270 nm）were tested.It was found that the types of pesticides detected by materials under different excitation wavelengths also changed.Compared with 1-Eu and2-Tb,the abilities of 15-Eu-Yb and 22-Tb-Yb for detecting TMT were improved.Experiments show that the kinds of pesticides detected by the materials can be changed by changing the excitation wavelength.