Studies On Zirconium-porphyrin Luminescent Metal-organic Frameworks In Fluorescence Analysis

Luminescent metal-organic frameworks（LMOFs）is a new type of porous crystalline luminescent material self-assembled by metal clusters and organic ligands.LMOFs combines characteristics of inorganic and organic materials and easy modification,which has flexible designability and abundant light-emitting points.Compared with other luminescent materials,it also has many advantages such as large specific surface area,adjustable pore size,and diverse spatial structures.Therefore,LMOFs have shown great potential in the fields of optical devices,information storage and fluorescence sensor.Porphyrin can be used as building units of LMOFs because of the unique planar rigidity and luminescent properties.At present,the application of porphyrin LMOFs mainly focuses on catalysis and photodynamic therapy,while the application as fluorescence sensing materials is still in the exploratory stage.Based on the above background,we expanded the application of porphyrin LMOFs in fluorescence analysis from the following three aspects:ligands,dimensions and modification methods.The specific contents are as follows:1.Benzoporphyrin ligand with larger rigid conjugated structure was synthesized by Lindsey method,and benzoporphyrin LMOFs were prepared.The optical properties of porphyrin and benzoporphyrin were studied with the response to various metals.Because of the high selectivity of benzoporphyrin to Cu²⁺and especially to Zn²⁺,benzoporphyrin was finally used as molecular probe to respond to Cu²⁺and Zn²⁺and further applied to the detection of Zn²⁺in actual water samples.2.Two/three-dimensional porphyrin LMOFs（UNs-FA and PCN-224）were synthesized,and their optical properties were compared.After the unique discoloration between porphyrin LMOFs and Cd²⁺was observed,the ratio fluorophore was modified on the surface of PCN-224 by the coordination of zirconium metal cluster and carboxyl group,and finally the ratio fluorophore determination of Cd²⁺was realized.3.Dual-emission composite MOFs that PCN-224 coated by UiO-66-NH₂ was synthesized using one-pot method by adding guest fluid to host precursor solution.The material was characterized by SEM,TEM,PXRD and FT-IR.As a fluorescent probe,it has been successfully applied to the response of pH in a wide area of water.