基于纳米碳材料DNA传感界面构建的转基因食品检测研究

There are urgent needs for high-throughput screening, low-cost, rapid and reliable detection of genetically modified foods (GMF) in GMF research & development, management, monitoring and identification. In this project, novel nanocarbon materials (such as carbon nanospheres, graphene, nano-SiC film) will be prepared, which will be biofunctionalized to build transducer interfaces with favorable properties of biocompatibility and optical-electric transition performances. Here, by selecting transgenic DNA of GMF as target, new methods will be developed for directly detecting transgenic DNA with ultra-low concentration on the fabricated transducer interfaces. The methods, which will be a powerful tools for transgenic research, are based on multi-way signal amplification strategies coupled with optical or electrochemical responses alterations before and after biorecognition events between the targets and detecting probes which are labled with fluorescent or electro-active labels. An in-depths study will be focus in the bio-functionalization, electron transfer, optical signal conversion, biocatalysis, biorecognition events (e.g., DNA hybridization), signal amplification mechanism on a molecular level at the bio-transition interfaces. At the same time, by exploring in different out-fields’ regulation of the basic properties and the factors affecting reaction kinetics, a new method based on nanocarbon materials for transgenic DNA biosensing will then be established.

在研究开发、管理、监督、甄别等方面，转基因食品对高通量、低成本、快速和可靠的检测方法有着迫切的需求。本项目拟制备新型纳米碳材料（如纳米碳球、石墨烯、纳米SiC膜等）并生物功能化，构建具有良好生物相容性和光电性能的纳米碳结构生物传感换能界面，以转基因食品DNA为目标物，采用荧光标记物或电活性分子标记DNA探针，利用生物识别事件前后光学或电化学响应信号的改变，结合多途径信号放大策略，创建对低浓度转基因DNA直接检测的新方法，为转基因研究提供有力的工具；从分子水平上，研究纳米碳结构生物换能界面的生物功能化、电子传输、光学信号转换、生物识别事件（如DNA杂交）效率与标记信号放大机制等基本行为；同时，深入探索外场对于上述基本性质的调控作用及反应动力学影响因素，进而创建基于纳米碳材料生物传感界面的转基因食品DNA分析新方法。

本项目围绕人们对食品安全与社会发展在分析检测方面的需求，针对传统检测方法耗时、分析灵敏度低和生物分子活性降低等问题，开展纳米材料生物功能化研究，构建高效的电化学生物传感器新方法。本研究合成了具有良好生物相容性的纳米材料，利用金-硫键，以捕获DNA将纳米复合物进行生物功能化，构建了DNA电化学生物传感换能界面，利用DNA杂交反应前后电化学响应信号的改变，结合信号放大策略，从而构筑了DNA电化学生物传感器，实现了对目标DNA序列（转基因DNA序列、沙门氏菌invA基因及自行设计的DNA序列）的灵敏检测；利用纳米材料的良好的生物相容性的特点，构筑了基于葡萄糖氧化酶的葡萄糖电化学生物传感器，实现了对葡萄糖的灵敏检测；利用rGO良好的物理性能，如大比表面积、高电子传输性能，组装了硫化物电化学传感器，实现了对食品中硫化物的灵敏检测。本项目集成了纳米材料及电化学分析方法的优点，为食品中有毒有害小分子及食品中的转基因DNA的检测提供了新的平台，对食品安全检测起到了促进作用。