基于仿生磁性石墨烯构筑球形DNA扩增的免疫传感器检测微囊藻毒素的研究

Microcystins (MCs) in the water quality safe and food safe have become a global focus on the environmental heath problems. This project aims to prepare antigens and antibodies of different MCs isomers, and then the signal-amplified immunosensors for MCs are prepared. During this process, a novel material, bionic magnetic graphene, which is prepared using polydopamine as heterogeneous adhesives to assemble magnetic particles on graphene, is used as the substrate of the immunosensor, while nanomaterial-marked spherical DNA amplified product, which is prepared from different DNA primers with the aid of hybridization chain reaction and rolling circle amplification, is used as the detection signal. After the investigation of the bioactivities of nanomaterials, not only can the synergetic peroxidase-like properties of graphene and magnetic particles increase the current response of the substrate, but also the extension effect of spherical DNA product can reduce the steric hindrance and increase the binding sites of probes, thus the sensitive and selective detection of MCs in aquatic products can be achieved. The completeness of this project will provide a new detection technology for MCs, a new analytical method for the environmental molecules and a new investigation tool for the construction of immunosensors. In addition, by analyzing the amount of MCs in different aquatic products and different watersheds, the risk exposure of MCs to consumers can be assessed by taking the aquatic products, thus it can provide theoritical basis for the contamination control and governance of MCs.

微囊藻毒素(microcystins，MCs) 带来的水质和食品安全问题已成为全球环境卫生组织关注的焦点。本项目将针对多种MCs异构体制备抗体，以聚多巴胺为纳米粘合剂在石墨烯表面异质组装磁性纳米材料作为免疫传感器的基底固定，以链式扩增、滚环扩增等新型DNA扩增方式制备球形DNA物作为免疫传感器的标记物，构筑具有增敏效应的MCs免疫传感器。在研究纳米材料生物活性的基础上，既协同利用石墨烯和磁性纳米材料类过氧化物酶的性质提高基底响应，又充分发挥球形DNA标记物在空间的延展效应减小空间位阻、增加探针结合位点提高末端响应，从而实现水产品中MCs的专一、灵敏检测。 本项目的完成，将为MCs的检测提供新技术，为环境小分子的分析提供新方法，为免疫传感器的研制提供新研究手段。并通过分析MCs在不同水产品和流域的分布情况，进而评估消费者食用水产品对MCs的暴露风险，为MCs的污染控制和治理提供理论依据。

微囊藻毒素(MCs)是目前已知的出现频率最高、产生量最大和造成危害最严重的藻毒素种类，其对水质环境和食品安全的危害已成为全球关注的环境卫生问题之一。建立灵敏、专一的 MCs 检测方法是今后进行预警并研究其危害的重要手段。.本项目针对微囊藻毒素的微量检测，制备了微囊藻毒素的抗原、抗体，以石墨烯、磁性纳米材料和硫化镉等一系列具有高比表面、优良电活性、优良光电活性的材料作为基底，以链式扩增、滚环扩增等 DNA 扩增技术等构建信号放大策略，建立了电化学免疫传感器、光电化学免疫传感器、可视化免疫传感器以及比率型的多信号免疫传感器，实现了对微囊藻毒素的特异性、高灵敏性的检测。项目研究过程中，详细研究了不同材料的形成机制、催化性能和生物活性，探讨了不同传感器的制备过程、界面电子传导和传感响应机理，并对各种影响因素和适用条件进行了探究。项目执行期间，在Analytical Chemistry, ACS Applied Materials & Interfaces, Journal of Materials Chemistry A, Biosensors and Bioelectronics等国际期刊共发表文章31篇，申请相关专利8项(授权4项)，参与编写专著《食品安全快速检测与预警》，培养研究生10余名。本项目构建的生物传感器为微囊藻毒素的检测方法提供了新手段、新策略，为环境小分子物质的检测提供了新路径、新方法，为免疫传感器的研制提供新思路、新途径。