Design And Drug Analysis Based On Fluorescent Carbon Quantum Dots Sensor

Drug residues will threaten the ecological environment and human health,so it is of great significance to establish fast and efficient analytical methods.Carbon quantum dots,a kind of monodisperse "zero-dimensional" carbon nanomaterials with the advantages of excellent fluorescence characteristics,optical stability,water solubility,and biocompatibility,have received widespread attention in recent years.Compared with the conventional organic dyes and metal semiconductor quantum dots,"green" carbon quantum dots whose raw material is a kind of renewable resource biomass have the advantages of a wide range of raw material sources,simple synthesis procedures,no strong acids or organic solvents needed,and excellent optical properties.Thus,it is very suitable for large-scale production and shows important society and economic value.In this paper,a fluorescent sensor based on carbon quantum dots is used to detect drug residues in food.The main contents are as follows:Firstly,carbon quantum dots were prepared from the biomass material mango peel by hydrothermal synthesis and further modified.Using mesotrione as a template molecule,3-aminopropyltriethoxysilane as a functional monomer,and adding ethyl orthosilicate for the construction of the polymeric structure,a highly selective fluorescence sensor was prepared in one step by a sol-gel method.Materials were characterized by transmission electron microscopy,X-ray photoelectron spectroscopy,etc.The effects of pH,excitation wavelength,solvent and other conditions on the fluorescence performance of the fluorescence sensor were investigated,and the mechanism of the fluorescence sensor was studied in depth.Finally,a fluorescence sensor was used to detect the content of the mesotrione in corn samples.The linear range was 15-3000 nmol/L,the detection limit was 4.7 nmol/L,and the recoveries were 91.4%-96.2%,the relative standard deviations were 3.2%-6.1%.The carbon quantum dots were prepared by the microwave-assisted synthesis method using the biomass material passion fruit peel.Ratiometric fluorescent sensors with high selectivity and strong anti-interference ability were synthesized by using carbon quantum dots and rare earth element europium as fluorescent components and tetracycline as template molecules,respectively.Its fluorescence performance was investigated and the synthesis procedures were optimized.The materials were performed by scanning electron microscopy,Fourier infrared,etc.The mechanism and selectivity of the fluorescence sensor were thoroughly studied.Finally,the fluorescence sensor was used to detect the content of tetracycline in milk.The detection of tetracycline has a good linear relationship at a concentration of 25-2000 nmol/L,the detection limit was 7.9 nmol/L,the recoveries were 95.8%-102.4%,and the relative standard deviations were 1.5%-3.6%.Using the biomass material sunflower seed bark as the main carbon source,carbon quantum dots were prepared by hydrothermal synthesis.Dimetridazole as a template molecule,methacrylic acid and glycidyl methacrylate as functional monomers,ethylene glycol dimethacrylate as a crosslinking agent,azobisisobutyronitrile as an initiator and carbon quantum dots as the fluorescence components,a restricted fluorescence sensor with high selectivity and sensitivity was synthesized.The materials were characterized by transmission electron microscopy,Fourier infrared,etc.The quenching mechanism,selectivity and binding time were investigated thoroughly.Finally,the fluorescence sensor was used to detect the content of dimetridazole in eggs.The linear range was 50-5000 nmol/L,and the detection limit was 16.2 nmol/L.The recoveries were 94.6%-105.2%,and the relative standard deviations were 2.7%-5.4%.