Study On The Construction Of Dye-supported Metal-organic Skeleton And Its Fluorescence Recognition Performance

The development of global urbanization and industrialization has led to increasingly serious environmental pollution.Water pollution is considered to be one of the problems threatening human life among all other types of environmental pollution.Water pollution is a kind of man-made pollution,including industrial pollution,agricultural pollution and domestic pollution.The treatment and detection of NACs and antibiotics are particularly critical.Therefore,it is urgent to develop an efficient,reliable,and low-cost technology to detect and analyze these environmental pollutants.Metal organic frameworks(MOFs)are crystalline,porous,and functional inorganic materials assembled by metal central clusters and appropriate organic ligands through coordination bonds.Due to its diverse structure,strong flexibility,and adjustable specific surface area,it has been designated as a fascinating inorganic material for the 21 st century.Currently,it has been successfully applied in fields such as fluorescence detection、light-emitting devices and biological imaging.The advantages of MOFs materials make them an economical and portable fluorescent probe for detecting and analyzing harmful substances in water bodies.In order to change the drawbacks of traditional detection instruments and single emission MOFs fluorescence detection and improve the accuracy of detection results,luminescent sensors with dual emission platforms have become more promising fluorescent sensing materials.In this thesis,we successfully prepared a dual emission MOFs luminescent sensor by selecting fluorescent dye molecules that are cheap and readily available and have excellent luminescent properties,encapsulating the dye molecules in highly stable luminescent MOFs.And performing fluorescence recognition for NACs and antibiotics in water.The research content of the paper is as follows:(1)MOF-808 was successfully synthesized by a simple hydrothermal method,and two new functional composites were successfully prepared by introducing eosin Y(EY)and rhodamine B(RHB)into the zirconium based framework EY@Zr-MOF、RHB@Zr-MOF.Through experimental testing,two dye@Zr-MOF Both display two fluorescence emission signals,the former originating from ligands and the latter from dye emission.Given this observation,both dye@Zr-MOF two signal sensors that can be used for fluorescence detection.Subsequently,their fluorescence recognition of nitroaromatic compounds was studied.The results indicate that,EY@Zr-MOF 、RHB@Zr-MOF composites are highly sensitive to NACs,especially to p-nitrophenol(4-NP)with high selectivity and sensitivity,and compared with Zr MOF detection performance.It was found that dye@Zr-MOF There is a lower detection limit and a higher quenching constant,indicating that dye encapsulation can improve the fluorescence and detection performance of the material.In addition,dye@Zr-MOF fluorescence quenching mechanism between NACs was analyzed,it is speculated that it is a comprehensive effect of resonance energy transfer,photoinduced electron transfer,and energy competitive absorption.(2)MIL-100(Sc)was successfully synthesized by solvothermal method,and two novel fluorescent composite materials with dual emission were successfully prepared by introducing dye eosin Y(EY)and methylene blue(MB)molecules into the scandium based framework,respectively EY@Sc-MOF、MB@Sc-MOF.Be based on dye@Sc-MOF the fluorescence sensing performance of antibiotics was investigated by using the ratio of relative fluorescence intensity instead of absolute fluorescence intensity as the output signal for different peak positions and peak intensities of the two fluorescence peaks.The results show that,EY@Sc-MOF、MB@Sc-MOF these two composite materials can be used as self calibrating sensors for highly selective detection of antibiotics,especially for the detection of nitrofuran antibiotics NFT and NFZ.In addition,after the recovery experiment,it was observed that the fluorescence response of the composite material to antibiotics did not significantly change and was highly stable.Finally,the exploration of the sensing mechanism can be attributed to the comprehensive effects of resonance energy transfer,photo induced electron transfer,and energy competitive absorption.Compared to a single fluorescent Sc-MOF material,two dye@Sc-MOF Composite materials exhibit higher selectivity,sensitivity,and accuracy.This study brings new prospects for designing dye encapsulated MOF dual emission fluorescence sensors to monitor antibiotics in water.And provides a new method for the detection of antibiotics in environmental systems.