基于离子印迹聚吡咯/三维多孔石墨烯的高灵敏Cd(II)电化学传感界面的构建

Cadmium (Cd(II)) ion is a common toxic heavy metal in water. For trace Cd(II) fast detection in water, this project presents a high-sensitive electrochemical Cd(II) sensing interface based on ion imprinted polypyrrole/three-dimensional porous graphene nanocomposite, which integrates ion imprinting technique, electrochemical technique, nano-modification technology and micro fabrication technology. The mechanism of Cd(II) imprinted in polypyrrole based on electropolymerization is discussed in order to provide the basis for the high mass transfer properties. The novel fabrication method of three-dimensional porous graphene as Cd(II) imprinted film substrate on microelectrode is proposed based on the method of electrochemical deposition on crystal template. The growth kinetic rule of three-dimensional porous graphene is investigated for a controllable construction technique. The interfacial coupling mechanism of the nanocomposite materials of ion imprinted polypyrrole/three-dimensional porous graphene is investigated. The nanocomposite with high surface area, high ratio of surface-imprinted sites and synergistic catalysis effect enhance the selectivity and catalysis activity, and the electrochemical Cd(II) sensing interface with high sensitivity can be obtained. Study the combination of the Cd(II) ion imprinted polypyrrole and three-dimensional porous graphene for Cd(II) sensing has theory innovation and method innovation on the aspects of improving the sensor sensitivity and selectivity in trace Cd(II) detection. This study will provide an important technological means for application of timely and efficiently monitoring and evaluating heavy metal pollution in water environment, and have great contribution to the society and economy.

本课题拟融合离子印迹技术、电化学技术、纳米修饰技术以及微加工技术，构建一种基于离子印迹聚吡咯/三维多孔石墨烯的高灵敏Cd(II)电化学传感界面，并将其应用于水质痕量Cd(II)的快速检测。采用电聚合方法，研究Cd(II)离子印迹聚吡咯作用机理，为离子印迹膜高传质性能的本质提供依据；通过电化学沉积胶体晶模板方法，创新性地研究有序三维多孔石墨烯印迹基质在微电极表面的电化学生长，考察三维多孔石墨烯生长动力学规律，获得可控生长技术方案；探索离子印迹聚吡咯/三维多孔石墨烯纳米复合材料产生高比表面积、多表面印迹位点、协同催化效应的界面耦合机制，获得高灵敏Cd(II)电化学传感界面。离子印迹聚吡咯与三维多孔石墨烯相结合的研究，在提高传感器对痕量Cd(II)检测的灵敏度和选择性方面具有理论和方法上的创新，为及时高效地开展水环境重金属监测及评价提供重要的技术手段，具有重要的科学与社会意义。

我国水环境重金属污染问题突出，痕量重金属检测已成为当前重要的研究课题之一。本项目融合纳米材料技术、离子印迹技术、电化学技术以及微加工技术，围绕电化学传感界面的传质性能和传电性能设计出新颖的基于离子印迹聚吡咯/三维多孔石墨烯的Cd(II)离子电化学传感器，有效地解决了目前水质重金属Cd(II)电化学传感器选择性和灵敏度两大关键问题。本项目采用光刻和喷墨打印等微加工技术成功制备出微电极芯片，为传感器微型化和批量化生产提供可能；采用电化学还原和化学自组装等方法制备三维多孔石墨烯，作为离子印迹膜印迹基底，重点考察了三维多孔石墨烯的可控化制备机理，有效提高了电极响应灵敏度；采用电化学聚合和紫外光聚合两种表面印迹方法在三维石墨烯表面原位聚合制备了重金属Cd(II)离子印迹膜，重点考察了吡咯功能单体与Cd(II) 模板离子的氨基配位的电化学固定及洗脱优化条件，建立了Cd(II)离子在印迹膜表面的电化学响应机制；重点研究了三维多孔石墨烯与离子印迹膜复合材料的界面耦合机制对Cd(II)的电化学增敏效应，制备出高灵敏新型水质重金属Cd(II)电化学微型传感器，实现了实际水样检测，满足了国家地表水I～V类水检测标准。