纳米材料增敏的高性能分子印迹膜电化学传感器的研制及其在环境激素检测中的应用

The molecular imprinted film-based electrochemical sensor(MIES) has great application and developing potential, but it has disadvantages of low sensitivity or slow mass-transfer rate. In this project, novel MIESs with high performance will be fabricated by electrochemical polymerization, which can combine polymerization, coating and doping into one step. We intend to improve the property of MIES through using nano-material functioned monomer, nano-material based substrate, co-polymerization of different monomer and optimizing polymerization conditions. To be specific, we will fabricate MIES using polymerizable mercpto-monomer loaded on nano-noble metals and nano-noble metal substrate immobilized on electrode surface; prepare MIES with high stability and conductivity and net-like structure through imprinting on the surface of multi-walled carbon nanotubes modified by organic, inorganic compound or ionic liquid; construct MIES by adopting substrate of catalytic nano-alloy coated carbon nanotube -ionic liquid composite and co-polymerizaion of two monomers. As the nano-materials have large area/mass ratio, high conductivity and electrocatalysis,two monomers can present better interaction with the template molecule,through these methods, the imprinted capacity, mass-transfer rate, selectivity and sensitivity of the obtained MIES can be greatly enhanced. At the same time, various techniques and methods will be used to explore the structure and property of MIES, and the effect mechanism of nano-material and the response mechanism of MIES will be discussed. On this basis, we intend to fabricate MIES with high performance and application feasibility, and furthermore to develop several methods for the sensitive detection of some typical environmental hormone. Therefore, the application and development of molecular imprinted technique will be greatly promoted through this project.

基于分子印迹的电化学传感器具有良好的发展前景，但目前尚存在传质速度慢、灵敏度低等问题。本项目拟采用集聚合、成膜、掺杂于一步的电聚合方法，并通过聚合单体纳米材料功能化、印迹基底纳米化、不同单体共聚以及调控电聚合参数等，研制纳米材料增敏的新型分子印迹膜传感器。具体拟以纳米贵金属负载的含巯化合物为功能单体，以纳米贵金属修饰电极为基底，制备多级纳米放大的复合印迹传感膜；在有机、无机物功能化的纳米碳表面电聚合，获取具高稳定性和导电性的网络结构印迹膜；用超声电沉积法制备碳纳米管-离子液体负载的具高催化活性的纳米合金，再在此基底上进行单或双单体电聚合印迹。由此提高印迹膜的印迹容量、传质速度、选择性和灵敏度。采用多种手段研究复合印迹膜的结构性能，探讨纳米材料的增敏机制和膜响应机理。进而研制实用性强的高性能分子印迹膜电化学传感器，建立某些典型环境激素的高灵敏检测方法。这将有力地推动分子印迹技术的应用与发展。

基于分子印迹识别膜的电化学传感器有良好的发展前景，但尚存在传质速度慢、灵敏度低、选择性有待进一步提高等问题。项目采用集聚合、成膜、掺杂于一步的电聚合方法以及易批量制备的化学聚合方法，通过聚合单体纳米材料功能化、印迹基底纳米化、多单体共聚等，研制出多类纳米材料增敏的新型分子印迹膜传感器。主要研究内容为：（1）以纳米贵金属/合金、纳米碳材料以及它们的复合材料作为印迹传感膜的负载基底，在保证印迹容量的同时降低膜层厚度，缩短识别与洗脱时间。（2）将单体或链转移剂通过自组装、离子交换、物理吸附、点击反应等固定到纳米金属或碳材料表面，制备纳米化功能单体，增强印迹聚合膜的导电性与纳米化程度。将纳米结构印迹膜原位或离线修饰到纳米基底表面，制备基于纳米材料多级放大效应的新型分子印迹电化学传感器。（3）使用双单体共聚改善印迹膜的识别灵敏度和抗干扰能力。（4）采用显微、波谱、电化学等手段考察复合印迹膜的结构、性能，探讨纳米材料增敏机制和膜响应机理；（5）研制实用性强的高性能分子印迹膜电化学传感器，建立典型环境激素、农残、药物分子的高灵敏检测方法。研究结果表明：（1）印迹基底纳米化及构筑三维网络复合纳米结构是制备高灵敏高选择性印迹传感薄膜最简单有效的方法（信号提高数倍至数十倍）。（2）功能单体纳米化是获取导电性优、传至速度快的小颗粒、大容量分子印迹膜的有效途径，负载到碳纳米管表面的可聚合离子液体是最为典型的纳米化功能单体。（3）双单体共聚能进一步提高传感膜的灵敏度（增加0.5-1倍）和选择性，膜表面亲水性“分子刷”的引入能有效提升印迹膜的亲水性和选择性。（4）基于纳米材料增敏效应的分子印迹电化学传感器选择性好，可用于实际样品中环境激素、农残等的分析，检测下限一般可达nM级。有关研究为新型表面分子印迹电化学传感器的研制提供了多种设计思路与制备方法，将有力地推动分子印迹技术的应用与发展。