Preparation Of Carbon Quantum Dots Molecularly Imprinted Fluorescence Sensor And Its Detection Behavior For Tetracycline In Aquatic Environment

Tetracyclines（TCs）,as one of the most widely used antibiotics,have been detected in water for many times,which has acused serious impact on human health and ecological balance.It is urgent to detect TCs,but the effect of traditional methods is not ideal.Fluorescence analysis based on carbon quantum dots is an emerging detection method.It is widely used in the detection of various toxic and harmfu substances because it does not require complex pretreatment,simple operation,rapid response,low detection limit and high sensitivity.However,due to its poor selectivity,and the detection process is susceptible to interference from other substances.Molecularly imprinted polymers（MIPs）are a kind of special materials that can specifically recognize the target.Combining quantum dots with MIPs to prepare carbon quantum dots molecularly imprinted fluorescence sensors not only can detect specific targets,but also provide protection for the carbon quantum dots by the imprinting layer,which makes the physical and chemical properties of the carbon quantum dots more stable.Therefore,the use of carbon quantum dots molecularly imprinted fluorescence sensors to detect TCs in water has become a hot topic in recent years.In this paper,carbon quantum dots（C QDs）were prepared as fluorescent material by hydrothermal method.Using the tetracycline（TC）as template molecule,the C QDs molecularly imprinted fluorescent sensors were prepared by using three methods:sol-gel,precipitation polymerization and dopamine polymerization.The morphology,structure and optical properties of the prepared samples were studied by various characterization methods.The best detection conditions were determined by fluorescence detection experiments.Under the optimal detection conditions,the selective recognition and quantitative detection of TC for carbon quantum dots molecularly imprinted fluorescent sensors prepared by different polymerization methods were studied.The main research of this paper is as follows:（1）Carbon quantum dots molecularly imprinted fluorescence sensors（MIPs-SiO₂/C QDs）were prepared by sol-gel method.The morphology,structure and optical properties of the prepared samples were studied by TEM,FT-IR and fluorescence spectrophotometer.The optimum conditions of MIPs-SiO₂/C QDs for TC detection were determined by studying its concentration,stability and optimal response time to TC.Under the optimal detection conditions,the ability of MIPs-SiO₂/C QDs to detect TC quantitatively and selectively were studied,and it was successfully applied to the detection of TC in water environment.（2）Acrylic acid（AA）was used to modify vinyl groups on the surface of C QDs and used as fluorescent materials.Carbon quantum dots molecularly imprinted fluorescence sensors（MIPs-AA/C QDs）were prepared by precipitation polymerization.The morphology,structure and optical properties of MIPs-AA/C QDs were studied by TEM,FT-IR and fluorescence spectrophotometer.The optimum conditions of MIPs-AA/C QDs for TC detection were determined by studying its concentration,stability and optimal response time to TC.Under the optimal detection conditions,the ability of MIPs-AA/C QDs to detect TC quantitatively and selectively were studied,and it was successfully applied to the detection of TC in water environment.（3）Carbon quantum dots molecularly imprinted fluorescence sensors（MIPs-DA/C QDs）were prepared by dopamine polymerization.The morphology,structure and optical properties of MIPs-DA/C QDs were studied by TEM,FT-IR and fluorescence spectrophotometer.The optimum conditions of MIPs-DA/C QDs for TC detection were determined by studying its concentration,stability and optimal response time to TC.Under the optimal detection conditions,the ability of MIPs-DA/C QDs to detect TC quantitatively and selectively were studied,and it was successfully applied to the detection of TC in water environment.