可控纳米复合传感界面结合多重信号放大用于电化学免疫传感体系的构建及其生物分析应用

With the rapid development of nanoscience and nanotechnology, the introduction of functionalized nanomaterials with controllable morphology into the investigation of electrochemical sensing can be used to realize the construction and regulation of novel sensor interface to solve existing problems in the field of analysis such as early disease diagnosis and so on. It has become an inevitable trend of the development of electroanalytical chemistry and one of the technical difficulties in this field. In this project, novel liquid-liquid interfacial polymerization method is used to prepare molybdenum disulfide/poly(3,4-ethylenedioxythiophene) derivative nanocomposites with layered structure, which possess unique physical and chemical properties of nanomaterials and excellent conductive properties of conductive polymers. The thickness and microstructure of the composites can be adjusted by changing the polymerization conditions and the type of monomer derivatives. And, an immune-sensing interface with controllable morphology and thickness, excellent biological compatibility, and good conductivity is built. Then, in combination with biotin-avidin system, a multiple amplified electrochemical immunosensor for Streptococcus suis (an important zoonotic pathogenis) is developed by using two kinds of artificial enzymes (hemin/G-quadruplex and Au nanoclusters) as signal probe and Au nanoclusters-graphene oxide nanocomposite as signal nanocarrier. The smooth implementation of the project will provide a new platform for the early diagnostics of disease, which has important theoretical significance and a potential value for practical application.

伴随着纳米科学和纳米技术的快速发展，将形貌可控的功能纳米材料引入到电化学传感研究中，实现新颖传感界面的构建和调控以解决疾病早期诊断等分析领域存在的问题，是目前电分析化学发展的必然趋势和技术难点之一。本项目拟采用新颖的液-液界面聚合法，制备兼具纳米材料独特物理化学性能和导电聚合物优良导电性能的层状二硫化钼/聚(3,4-乙撑二氧噻吩)衍生物纳米复合材料，通过改变其聚合条件和单体衍生物类型，调节复合材料的厚度及微观结构, 构建形貌、厚度可控、生物兼容性好、有利于电子传递的免疫传感界面。然后，以G-四链体/血红素和金纳米簇两种人工模拟酶为信号探针, 氧化石墨烯为信号载体，再结合生物素－亲和素体系，发展一种简单快速的多重信号放大夹心免疫分析方法，用于猪链球菌（一种重要的人畜共患病原菌）相关抗原的高灵敏检测。该项目研究成果有望为疾病早期诊断提供新的检测平台，具有潜在的生物医学理论意义和临床实用价值。

将形貌可控的功能纳米材料引入到电化学传感研究中，实现新颖传感界面的构建和调控以提高生物传感的检测性能，是目前电分析化学发展的必然趋势和技术难点之一。本项目基于系列不同形貌和结构的纳米材料，聚(3,4-乙撑二氧噻吩)(PEDOT)，二硫化钼(MoS2)，二硫化钨(WS2)，普鲁士蓝(PB)，还原石墨烯(rGO)，石墨烯气凝胶(GAs)及其复合材料，并将这些纳米材料用于电化学传感界面的构建。通过改变材料的制备条件和组成成分，调节材料的微观结构，以达到优化其性能的目的，从而提高传感检测的灵敏度和稳定性。结合生物和纳米组装技术，建立了基于抗原-抗体的免疫传感体系及构建了新型纳米修饰电极体系，实现了对生物蛋白、生物小分子、农药医药分子、重金属等的高灵敏检测，为疾病诊断、药物检测、食品安全检测等相关重要问题提供了理论基础和技术支持。（1）基于抗原-抗体的免疫传感体系研究。a）采用界面聚合方法制备了AuNPs/PB-PEDOT和AuNPs-PEDOT/PB-rGO，通过在界面上组装抗体，构建了高灵敏电化学免疫传感平台。b）以聚(5-羧基吲哚) (PIn-5-COOH)为核，制备了核壳结构PIn-5-COOH@PEDOT，结合化学交联方法，构建了灵敏的免疫传感平台。c）以GAs和钛酸钠微球(M-NTO)为核，制备了PEDOT-GAs和M-NTO-PEDOT，利用AuNPs固定抗体，构建了灵敏的免疫传感平台。d）合成了氮化石墨烯-AuNPs-壳聚糖(N-GS-AuNPs-Chit)，构建了免标记免疫传感平台。e）制备了MoS2/GAs复合材料，利用AuNPs固定抗体，构建了免标记电化学免疫传感平台。（2）新型纳米修饰电极的制备研究。a）以PEDOT为主干材料，制备了PEDOT:PSS，UIO-66/PEDOT和PEDOT/EDTA-Co，作为电极材料用于生物小分子和药物分子的电化学检测。b）以GO作为前驱体制备了rGO基复合材料，GAs基复合材料，以这些材料修饰电极构建了电化学传感器用于重金属离子、食品添加剂、农药残留等有害物质的检测。