分级多孔空心金属氧化物/石墨烯复合材料的设计、合成及其在恙虫病检测中的应用研究

Taking the early diagnosis of tsutsugamushi disease as the entry point, our project was to develop a type of metal oxide/graphene composite-modified electrochemical tsutsugamushi disease DNA sensor electrode, which was on the basis of DNA biotechnology and electrochemical sensor technology and aimed at increasing the loading amount of orientia tsutsugamushi ssDNA probe on the surface of the electrode and enhancing the electrochemical response of electrode to hybridization reaction indicator. The design of hierarchical porous structure led to the achievement of the expansion of the specific surface area of the modified electrode material and the diffusion facilitation of probe molecules on the electrode surface, which is greatly beneficial to the immobilization ability of the electrode to the ssDNA probe. By means of the collaborative catalytic system, defect engineering and the exposure of the active crystal face, the catalytic active site of the material was accrued, the active site exchange frequency was raised, the intrinsic catalytic activity of the material was enhanced and the electrochemical response of electrode to hybridization reaction indicator was accelerated. Based on the regulation and control of the interface interaction, the material resistance was declined, the electronic transmission route was shortened, the electron transport dynamics inside the material was upgraded and the sensitivity of the electrochemical response of electrode to hybridization reaction indicator was strengthened. The orientia tsutsugamushi DNA sensor electrode was established through specific DNA immobilization technology, and the structure and effect relationship between the modified electrode material and its properties was systematically researched. Furthermore, the amendment of the structure design of the modified electrode material stimulated the accomplishment of the high property orientia tsutsugamushi DNA sensor, which laid a solid foundation for the creation of efficient DNA sensor.

本项目以恙虫病的早期诊断为切入点，立足于DNA生物技术和电化学传感器技术，以提高电极表面恙虫病东方体探针ssDNA的固定量和增强电极对杂交反应指示剂的电化学响应为根本目的，基于金属氧化物/石墨烯复合物电极修饰材料构建恙虫病电化学DNA传感器电极。通过分级多孔结构的构建增大电极修饰材料的比表面积和促进探针分子在电极表面的扩散，提高电极对探针ssDNA的固定能力；通过构建协同催化体系、缺陷工程、活性晶面暴露等手段，增加材料的催化活性位点和提高活性位点交换频率，提高材料的本征催化活性，增强电极对杂交反应指示剂的电化学响应；通过界面相互作用的调控，降低材料内阻和缩短电子传输路径，提升材料内部的电子传输动力学性能，增强电极对杂交反应指示剂的电化学响应灵敏度。系统研究电极修饰材料结构与性能之间的构效关系，实现高性能恙虫病东方体电化学DNA传感，为高效DNA传感器的创制奠定基础。

本项目以恙虫病的早期诊断为切入点，立足于生物传感技术和电化学技术，以提高电极表面生物探针DNA的固定量和增强电极对杂交反应指示剂的电化学响应为根本目的，基于金属氧化物复合物电极修饰材料构建高性能电化学传感器电极并应用于恙虫病检测。课题组首先通过生物技术对恙虫病东方体DNA进行提取、分离和解析，确定恙虫病的保守基因序列（sta56），根据遗传信息学的方法获得基因抗原表位，并采用PCR技术对其扩增获得ssDNA。基于“协同刻蚀沉淀”等策略等实现氧化物复合物电极材料的制备。采用特定的固定技术，构建生物传感器电极，并应用于恙虫病东方体DNA检测，系统研究电极修饰材料结构与性能之间的构效关系。结果显示，通过设计特殊的分级多孔结构增大了电极修饰材料的比表面积和促进探针分子在电极表面的扩散，提高电极对探针ssDNA的固定能力，通过构建协同催化体系、缺陷工程、活性晶面暴露等手段，增加材料的催化活性位点和提高活性位点交换频率，提高材料的本征催化活性，增强电极对杂交反应指示剂的电化学响应，实现高性能的电化学传感。综上所述，为高效DNA传感器的创制奠定基础。项目资助各项研究进展顺利，发表SCI论文26篇，培养博士研究生3名，研究生10名。目前博士研究生在读，硕士研究生6名已毕业，4名在读。项目投入经费37.00万，支出为34.7751万元，各项支出基本与预算相符，结余2.2249万，剩余经费计划用于该项目研究的后续支出。