The Preparation Of Imprinted Fluorescence Sensor And The Research Of Their Selective Detection Of Fluoroquinolones

The molecularly imprinted sensor has the ability to specifically recognize a target molecule by a molecularly imprinted polymer,and when the molecularly imprinted polymer adsorbs the target,there will be a change in physical or chemical signals.These signals are converted into quantizable output signals by signal converters,and the target signals are analyzed and detected by detecting the output signals.In this paper,a novel molecularly imprinted fluorescent sensor for analysis and detection was prepared by combining the special recognition of molecularly imprinted sensor with the high sensitivity of fluorescence detection technology.Compared with traditional instrument detection methods,molecularly imprinted fluorescence sensors not only have high accuracy and sensitivity,but also have low selectivity and low detection cost.Compared with traditional biosensors,molecularly imprinted fluorescence sensors are not only selective and recognizable,but also It has good mechanical stability,simple preparation,low cost and reusability.Therefore,the development of molecularly imprinted fluorescence sensors and their application in the rapid detection of environmental pollutants has become a research hotspot in the fields of environmental monitoring,food safety and public health.The main work was as following:（1）A novel molecularly imprinted fluorescence sensor was prepared by distillation precipitation method for the detection of trace amounts of ciprofloxacin（CFX）in actual environmental water samples.The fluorescent material FITC was grafted onto the surface of SiO₂ with active amino groups by using the organic dye fluorescein isothiocyanate FITC as the fluorescent material and APTS as the active agent.Next,using CFX as a template molecule,AM as a functional monomer and EGDMA as a cross-linking agent,a molecularly imprinted fluorescence sensor MIPs@SiO₂-FITC with a core-shell structure was synthesized under the initiation of AIBN.The morphological and structural characteristics of MIPs@SiO₂-FITC were studied by various characterization methods.The results show that the molecularly imprinted fluorescence sensor achieves fast,sensitive and highly selective detection of CFX compared to conventional detection techniques.The detection limit is as low as 4.04 nM,and the detection linear range is 4.04²50 nM,showing a lower detection limit and a wider detection range.Analysis of actual environmental water samples shows that MIPs@SiO₂-FITC has good prospects in practical applications.（2）Synthesis of aqueous phase CdTe QDs with yellow fluorescence using MSA as a protective agent.Then,followed by reverse phase microemulsion method,molecularly imprinted fluorescent sensor MIPs@SiO₂@CdTe was synthesized with APTES as the functional monomer,norfloxacin（NFX）as the template molecule and TEOS as the crosslinking agent,and was used for selective identification and fluorescence detection of norfloxacin.The morphology and structure of MIPs@SiO₂@CdTe and the optimization of fluorescence detection conditions were studied by various characterization methods.The results showed that the size distribution of MIPs@SiO₂@CdTe was uniform and had a core-shell morphological structure.Basically,each SiO₂ shell only covered one CdTe quantum dot.Overlay a CdTe quantum dot.The specific recognition performance of MIPs@SiO₂@CdTe for target molecule NFX was studied by fluorescence detection.The linear concentration range of NFX was accurately detected from 3.82 to 150 nM,and the detection limit was LOD=3.82 nM.It was successfully applied to the actual sample.Detection analysis.（3）The mesoporous silica was synthesized by a sol-gel method and wrapped with red fluorescent CdTe quantum dots,and its surface was modified by KH-570.Then,with Lomefloxacin（LFX）as template molecule,AM and MAA as common functional monomers,and cross-linking agent EGDMA were added to synthesize molecularly imprinted fluorescence sensor MIPs@KH570-MSiO₂@CdTe,which was used for qualitative and quantitative detection of LFX.The detection instrument is used to characterize the fluorescence sensor with a special core-shell mesoporous structure,good fluorescence stability,and can quickly respond to the target.The fluorescence sensor has a good linear relationship between 3.75 and 120 nM,and the linear regression equation F₀/F-1=0.0055C-0.0059 is established.The correlation coefficient is R²=0.9970 and the detection limit is LOD=3.75 nM.