Construction Of CP/LnMOF Composite White Light Bodies And Detection Of Trace Antibiotics In Water

Since the discovery of penicillin,the first antibiotic,in 1928,antibiotics have developed into drugs that can prevent and treat diseases.In addition to treating human diseases,antibiotics are also widely used as feed for livestock and aquatic products,leading to their inevitable discharge into water.Because antibiotic molecules are difficult to biodegrade,they provide a breeding ground for antibiotic-resistant bacteria and form antibiotic-resistance genes.For this reason,organizations around the world generally limit the concentration of antibiotics in water to less than nanomolar.In recent years,however,environmental scientists have found that concentrations of antibiotics in many seas,rivers and even drinking water exceed tolerable standards,posing a threat to human health.Therefore,for the dual consideration of environmental protection and human health,it is urgent to develop an effective method to determine the concentration of antibiotics in water qualitatively and quantitatively.Therefore,the following two studies are designed and completed in this paper.Firstly,two two-dimensional lanthanide metal-organic framework materials with sql topology,[Eu(HDPA)(DPA)]_n(Eu DPA)and[Tb(HDPA)(DPA)]_n(Tb DPA)(H₂DPA=2,6pyridine dicarboxylic acid),were prepared by hydrothermal method.The material has high thermal and water stability and exhibits excellent fluorescence properties.The g-C₃N₄@Eu_0.3Tb_0.7-MOF hybrid composite was prepared by one-pot method with the blue-emitting g-C₃N₄carbon nanomaterials and Ln-MOF,and the white light composite with high quantum yield(57%)was obtained by adjusting the proportion of each component.Importantly,the white light composite exhibits excellent fluorescence properties,high selectivity and sensitivity to tetracycline hydrochloride(TC),which makes it a good candidate material for water quality monitoring antibiotics and has practical value.In addition,two kinds of white light composite films were designed and prepared.One is that MOF-76(Eu_0.05Tb_0.95)with blue emission carbon dot(CD)and yellow emission is anchored on the polyvinyl alcohol(PVA)substrate.Due to hydrogen bond interaction,the luminescent group CD and MOF-76(Eu_0.05Tb_0.95)have uniform dispersion and enhanced thermal and environmental stability in terms of structure and photophysical properties.Notably,this white light-emitting film exhibits unusual sensitivity to carbamazepine(CBZ)in water,urine and serum samples with detection limits up to nanomolar levels by sensing luminescent discoloration from white to blue.The mechanism analysis of the system showed that CBZ molecule was adsorbed on the benzene ring of 1,3,5-homophthalic acid ligand in MOF-76(Eu_0.05Tb_0.95)through?-?interaction.Then photoinduced electron transfer occurs,resulting in enhanced blue fluorescence and quenching of green and red fluorescence.The second method is to prepare blue light polymethyl methacrylate polymer(PMMA)and yellow light MOF(Eu_0.3Tb_0.7-D-DBTA)by solvothermal method.The rare earth complex is bonded with PMMA by hydrogen bond,and the white light film can adsorb melamine to realize the fluorescence color sensing from white to blue.The prepared white light composite material can be used as a light-emitting sensor for color change sensing.The sensor has advantages in stability,sensitivity,selectivity,and can detect the color change of antibiotics in water,which further suggests its portability,rapid and accurate application prospect.