多维功能化石墨烯复合材料电化学适配体传感器检测海洋致病细菌的研究

Multi-dimensional functionalized graphene nanocomposites exhibit many specific properties such as large surface area, high conductivity and good biocompatibility. Aptamers are oligonucleotides that show high specificity and strong affinity to the target molecules. Electrochemical biosensors have the characteristics including high sensitivity, low cost and easy operation. In this project the controllable synthesis of multi-dimensional functionalized graphene nanocomposites are planned to be realized by different methods, which are further applied to the fabrication of electrochemical aptamer sensors. The synthesis procedure of the graphene based nanocomposites will be optimized and further used to the preparation of various kinds of nanocomposite modified electrodes. Then the immobilization methods such as self-assembly, covalent binding, electrostatic attraction etc. of aptamers for pathogen will be selected to get an aptamers decorated interface. The aptamers on the electrode surface can interact with the target pathogen with high specificity and affinity, which can result in the structural changes of the electrode interface. By combining various electrochemical detection methods with labeled or unlabeled procedure, peak current or impedance can be used as the signal for monitoring the binding reaction. Then new electrochemical methods for the detection of different kind of pathogens including Staphylococcus aureus, Escherichia coli, Salmonella, Vibrio parahemolyticus, Listeria monocytogenes etc. can be achieved with high sensitivity and selectivity. And the proposed methods will be applied to the detection of marine samples such as marine products or water samples. Also the simultaneously detection of different pathogens in the same sample will be investigated. This research will extend the applications of functionalized graphene based nanocomposites in the field of electrochemical aptamer sensors for pathogens in marine samples.

多维功能化石墨烯复合材料具有比表面积大、导电性高、生物相容性好等优点，适配体具有特异性好和亲和力强的特点，电化学传感器具有灵敏度高、成本低、操作简单等优点。本项目拟开展多维功能化石墨烯复合材料的可控合成及其在电化学适配体传感器中的基础研究，优化多维功能化石墨烯复合材料的合成方法，组装功能化石墨烯复合材料修饰电极界面，优化致病细菌适配体在修饰电极表面上的固定化方法，设计多种电化学信号的检测方法与策略，利用核酸适配体与目标细菌之间发生特异性结合反应之后会引起电极界面的结构变化，采用标记法与非标记法，利用电流和电阻等可测电化学信号，实现致病细菌的电化学适配体传感检测，并将该方法应用于多种致病细菌如金黄色葡萄球菌、致病性大肠杆菌、沙门氏菌、副溶血弧菌、单增李斯特菌等的高灵敏检测，及各种海洋样品如海产品和海水中致病细菌的检测，实现多组分细菌的同时检测，进而建立海洋产品中致病细菌的高效检测新方法。

本项目以二维石墨烯纳米片为基础，结合其他碳基功能材料如石墨炔、碳纤维、生物质碳、MOF衍生碳等，以及多种新型材料如黑磷烯、MXene、纳米金、ZnO纳米棒等，采用水热合成、静电纺丝、高温碳化等方法构建了多维石墨烯复合材料、生物质碳基复合材料、碳纤维复合材料、MOF衍生碳材料等系列新型碳基复合材料，将这些功能复合材料应用于化学修饰电极和电化学传感器，特别是基因传感器和适配体传感器方面的研究，采用滴涂、电沉积、自组装等方法，将纳米复合材料固定在金电极、玻碳电极、碳离子液体电极和ITO电极等电极表面后，进一步固定氧化还原蛋白酶，海洋致病微生物如金黄色葡萄球菌、致病性大肠杆菌、副溶血弧菌、单增李斯特菌的特征基因序列和适配体序列，形成相应的电化学生物传感器。利用复合材料的优点如导电性好、比表面积大、孔隙率高、生物相容性好、催化活性高、三维空间网络结构、负载量大等优点及每种材料之间存在的协同作用，并利用多种适配体传感模式，如G-四链体和光电化学信号检测方式如光电信号、阻抗信号、电化学指示剂电信号等，建立多种新型电化学和光电化学适配体传感体系，并用于海洋致病细菌的检测和相应特征序列基因检测，以及某些代表性重金属离子的检测。.项目共发表相关科研论文39篇，其中SCI收录论文37篇，申请国家发明专利11项，项目组成员参加10个国内学术会议，培养研究生8名，包括博士研究生3名，硕士生5名。