Construction Of Fluorescent Probe Based On Coordination Polymer And Detection Of Small Orginic Molecules

The fluorescence sensing technology have many advantages,such as simple,fast,short response time,real-time in-situ detection and visual detection.Coordination polymers have attracted the attention of researchers as a new type of fluorescent sensing materials,and has been widely used in many fields such as the monitoring of cations and anions,organic small molecules,biological imaging and so on.In this paper,the fluorescence sensing of water-soluble vitamin folic acid and tetracycline antibiotics were studied.The coordination polymers that can be exfoliation into ultra-thin two-dimensional?2D?nanomaterials and modified by amino functional groups were designed and synthesized respectively,which can achieve high sensitivity and selectivity detection of target analytes.In the first part,a series of coordination polymers?CP1^CP6?with different free amino content were synthesized under solvothermal conditions.The results show that the coordination polymers are homogeneous and have excellent fluorescence properties.Folic acid?FA?quenched the fluorescence of these coordination polymers in a concentration dependent manner.The detection limits of CP1 and CP6in the fluorescence experiment results were 2.82×10^-6 M and 1.7×10^-7 M,respectively,which indicating that the presence of amino groups in the structure can effectively sensitize the sensitivity of FA responses.In the second part,the ultra-thin 2D nanosheets has attracted a lot of attention because of its unique structure,large surface area and good stability.We successfully synthesized 3D structures stacked by van der Waals forces.Subsequently,a liquid-assisted ultrasonic exfoliation technique was used to prepare ultra-thin 2D nanosheets with a thickness of about 2.5 nm,which is the thickness of a single 2D sheet layer in the crystal structure.These nanocomposites exhibit excellent fluorescence properties and can detect tetracycline antibiotics with high sensitivity and selectivity.Among them,the detection limit of CP7 for tetracycline?TC?is 2.16×10^-8 M.In the third part,based on the previous works,the bpeb ligand modified with amino group as the functional group,and constructed CP9with 4,4'-Oxybis?benzoic acid?as the bridging ligand.By comparing the powder diffraction analysis,CP9 and CP7 are isomorphic,and then the fluorescent material with thickness of about 10 nm is obtained by further ultrasonic treatment.It can be used as a fluorescent sensor to detect tetracycline antibiotics and 2,4,6-Trinitrophenol.