Fluorescence Sensing Analysis Of Antibiotics Based On Metal-organic Framework Materials

Environmental residues of antibiotics can lead to the spread of drug-resistant genes,seriously endangering the micro-ecosystem,and can be enriched through the food chain and eventually ingested by humans,posing a great threat to health.Therefore,the development of techniques for sensitive detection and efficient removal of antibiotic residues in the environment is extremely important,but also extremely challenging.Fluorescence-based analytical methods have gradually become one of the research hotspots due to their efficiency,convenience,portability,and high sensitivity.Moreover,compared with traditional methods for the removal of antibiotics from wastewater,adsorption-based methods are considered to be one of the most promising methods because of their simplicity of operation,low cost,and absence of secondary contamination.Metal-organic frameworks(MOF)are an emerging class of porous crystalline materials.A large number of MOF have unique fluorescent properties and are sensitive to external stimuli,making it possible for them to be designed as fluorescent probes.Furthermore,considering the large specific surface area and adjustable pore size of some fluorescence-emitting MOF materials,the integration of adsorption capacity into fluorescent probes has proven to be an effective strategy for contaminant sensing and adsorption.Therefore,this paper focuses on the design and synthesis of functional MOF materials and explores their applications in the highly sensitive fluorescence sensing of oxytetracycline and malachite green and sensing/adsorption of nitrofuran antibiotics.The details are as follows:1.For the first time,aluminum-organic framework with microflower morphology and abundant surface open aluminum sites,FMIL-53(Al),was constructed by acetic acid-assisted solvothermal method and applied for the ultra-sensitive detection of oxytetracycline(OTC).FMIL-53(Al)possesses abundant open aluminum sites on its surface,which can selectively cooperate with OTC to fix the molecular conformation.The OTC molecules underwent a transition from twisted conformation to extended conformation,accompanied by increased green fluorescence intensity at 520 nm.As a fluorescence probe,the detection limit of FMIL-53(Al)for OTC is estimated as low as 0.94 nM,making it one of the most sensitive fluorescent probes for OTC applications.2.By encapsulation of blue-emitting dye(2-amino-terepthalic acid,NH2-BDC)into the nanopores of FMIL-53(Al),the ratiometric fluorescence probe NH2-BDC@MIL-53(Al)was prepared,and applied for sensing of OTC based on ratiometric fluorescence.For sensing,the blue fluorescence intensity of NH2-BDC dye in the probe is constant,which can be used as a built-in reference.As for the analytical performance,the detection limit is estimated to be as low as 11 nM.Importantly,the smartphone-based color recognition App can identify the continuous color evolution of the ratiometric fluorescence probe caused by the addition of oxytetracycline(OTC),providing a rapid non-instrument-based field analysis method to achieve semi-quantitative detection of OTC.3.Eu3+-doped Zr-MOF:1-4-Eu/BPyDC@UiO-67 was prepared based on the"post-synthesis modification" method and used for the ratiometric fluorescence sensing of Malachite Green(MG).The red emission of the probe at 620 nm can be significantly quenched by MG,while the purple emission intensity at 415 nm barely changes,which can be applied to MG ratiometric fluorescence.The detection limit is estimated to be as low as 6.6 nM.Finally,the reliability of the proposed ratio fluorescence sensing strategy is verified in lake water samples.4.A dual-functional platform for simultaneous detection and removal of nitrofurans(NFs)from aqueous solutions was developed based on a water-stable luminescent UiO-type metal-organic framework(Zr-fcu-sti).For sensing,Zr-fcu-sti is one of the most sensitive luminescent MOF-based sensing materials based on an efficient luminescence "turn-off" response to NFs in parts per billion(ppb).Meanwhile,the appropriate pore size,large specific surface area,and widely distributed hydrogen bonding sites on the pore surface of MOF endow the material with good absorption ability for NFs in an aqueous environment.