食品中酚类雌激素环境响应分子印迹磁性复合微球构建、识别机理及应用研究

The pollution of phenolic estrogens (PEEs) for foods became more and more serious. The detection of PEEs in foods need complex pretreatment. Molecularly imprinted polymers (MIPs) have the ability to selectively enrich PEEs. However, the traditional MIPs has the disadvantages of insoluble in water, low mass rate, low adsorb ability, and difficult separation. The aims of this project was to synthesis environment-responsive functional monomers, and then develop (dual/multiple) environment-responsive and magnetic molecularly imprinted microspheres (ER-Fe3O4-MIMs) on the Fe3O4 surface by living polymerization, interpenetrating polymer networks, and grafted polymers brushes methods. The responsive mechanism of functional monomer structure was investigated by molecular dynamics simulation and advanced analysis method under different environment stimulation. In order to explore the recognition mechanism of ER-Fe3O4-MIMs from molecular level, the self-assemble, coordination, and response of molecularly imprinted sites were explained, and their relationships were further researched for developing relevant mathematical models. Food samples pretreatment method of ER-Fe3O4-MIMs was also developed. Combination of ER-Fe3O4-MIMs and capillary electrophoresis (CE) can achieve the goals of specific recognition, higher enrichment, quickly separation and high sensitivity detection for PEEs in food samples. The technologies of magnetic separation, environment-responsive polymers, MIPs and CE were applied in food fields in this project, and a novel detection method with high sensitive, high ability recognition in water, and simple separation was developed. Thus, the method of this project can detect trace PEEs in food samples.

食品中酚类雌激素(PEEs)测定需进行样品前处理，分子印迹聚合物(MIPs)可选择性富集PEEs。但传统MIPs水容性差、传质速率慢、结合容量低和分离困难。本项目拟合成环境响应性功能单体，以PEEs为模板分子，在Fe3O4表面，结合活性聚合、互穿聚合物网络和接枝聚合物刷技术构建环境响应分子印迹磁性复合微球(ER-Fe3O4-MIMs)。利用分子动力学研究环境刺激下功能单体与模板分子相互作用能、力场和结构变化，阐述印迹空穴在刺激信号下表现的自组装性、协同性和应答性，建立数学模型从分子水平上说明识别机理。发展ER-Fe3O4-MIMs前处理方法，结合毛细管电泳(CE)，实现对食品中PEEs的特异识别、高效富集、快速分离和高灵敏度检测。本项目将磁分离、智能高分子材料、MIPs和CE集成于食品领域，构建灵敏度高、水体识别力强、环境友好和快速分离新方法，实现对食品中痕量污染物快速分离高灵敏检测。

项目背景：随着工业的不断发展，大量的酚类雌激素被释放到环境中，并借助食物链不断传递并富集于人体，产生巨大的毒副作用。因此，开发酚类雌激素新型检测方法具有重要意义。主要研究内容：以不同酚类雌激素(如雌二醇，双酚A 等)为模板分子，合成了多种环境响应分子印迹材料(如拉链温敏型MIPs聚合物，磁性拉链式MIPs微球和磁性光响应MIPs微球等)及电化学传感器(如相转化MIPs传感器，MIPs纳米井电化学传感器和电子鼻MIPs传感器等)，并对他们的理化性质、吸附机理和传感性能进行了详细研究；同时，开发了一系列新型MIPs可视化传感器(如三荧光发射MIPs可视化传感器，MIPs比率荧光纳米传感器，MIPs多发射荧光传感器，MIPs双发射可控比率荧光传感器等)，并对食品中污染物进行可视化快速检测；重要结果及关键数据：研究发现上述环境响应性MIPs材料对酚类雌激素模板分子素具有良好的特异性识别和高效富集等优点，针对不同环境响应性能，构建了相对应的样品前处理方法，结合色谱等技术实现了对食品样品中酚类雌激素高灵敏度检测。MIPs电化学传感器具有多孔结构和高比表面积，模板分子能够快速的传递到MIPs识别位点并高效富集，进而阻碍了电极间的电荷转移，而显示出电化学检测信号的输出与变化。可实现对食品中酚类雌激素无标记、简便、快速高灵敏度检测效果。结合MIPs技术和荧光可视化技术，构建了MIPs可视化传感器，实现了对食品中污染物快速、高灵敏度和可视化检测。与传统分离分析方法相比，基于荧光响应的表面印迹传感器具有快速、检测过程简单、水相识别能力强和现场可视化等优点。科学意义：本课题研究内容充分利用了食品可惜、分析化学和材料化学等学科的交叉优势，构建了一系列MIPs材料及传感器，对食品中污染物具有分离、富集和检测具有极大应用潜能，为提高现场快速检测方法提高了新的技术支持和参考，为食品安全和人类健康做出一定贡献。