基于可控纳米组装体的SERS适体传感器超灵敏快速检测赭曲霉毒素A的研究

Ochratoxin A(OTA) is one kind of common mycotoxins with high toxicity, which can cause serious harm to human health and even death in people through OTA-contaminated food. There is tremendous academic value and practical significance to explore viable alternative for rapid screening of OTA in foods. In this project, we will develop a novel aptasensor for ultrasensitive and rapid detection of OTA in food with complex matrices based on surface enhanced Raman scattering (SERS) of controlled nano-assembly. OTA aptamer of high selectivity and affinity is combined with ultrasensitive SERS-based technology in this study, intending to construct a biosensor with excellent performance. And breakthrough in controlled assembly of gold nanorod (GNR) will be realized, including rapid and oriented decoration of DNA on the GNR surface and selection of optimum assembly configuration with significant local field enhancement. Tunable nucleotide sequence of the OTA aptamer and DNA, is also provided to covercome long-standing problems in SERS substrate materials-research societies about controlling the nanometre-gap and nanogeometry with high reliability and reproducibility. Additionally, detection protocol with GNR disassembly induced by specifically recognize aptamers free in solution to is employed, resulting in reduced identification difficulty and steric effect. The SERS aptasensor will be achieved by using nucleotide sequence controlled high-yield nano-assembly and OTA target molecules induced specific disassembly. Then, the optimum nucleotide sequence and effective Raman characteristic peak information will be selected to establish a quantitative model, in order for ultrasensitive and rapid determination of OTA in food with complex matrices. It may be potential to provide the theoretical basis for developing novel and rapid screening equipment of mycotoxins in food with China's independent intellectual property rights, which has important scientific significance and market value.

赭曲霉毒素 A（OTA）是一种典型的剧毒真菌毒素，可经由污染的食品对人类健康产生严重危害，发展新型快速检测技术以提高OTA的测定精度和效率，有巨大的学术价值和现实意义。项目提出一种基于可控纳米组装体表面增强拉曼散射（SERS）的新型适体传感器应用于食品复杂基质中OTA的超灵敏、快速检测。该研究将高选择性、亲和力的OTA核酸适体与超灵敏SERS技术结合，突破DNA快速定向修饰以及局域场增强显著的较优构型组装体选择困难的问题，并通过碱基序列精确控制金纳米棒自组装来克服SERS基底材料研究中纳米结构间隙和几何构象可靠性和重复性的瓶颈。同时选择游离形态的核酸适体特异性识别OTA诱导的金纳米棒解组装的检测模式，减少空间位阻和识别难度的同时建立有效的传感方法。通过优化碱基序列设计并有效拉曼特征峰信息的筛选建立OTA定量模型。研究成果可为研发具有我国自主知识产权的食品中真菌毒素快速检测装备提供理论基础。

赭曲霉毒素 A（OTA）是一种典型的剧毒真菌毒素，可经由污染的食品对人类健康产生严重危害，发展新型快速检测技术以提高OTA的测定精度和效率，有巨大的学术价值和现实意义。本项目提出了一种基于可控纳米组装体表面增强拉曼散射（SERS）的新型适体传感器应用于食品复杂基质中OTA的超灵敏、快速检测。本项目探索了头碰头、肩并肩金纳米棒组装结构的构建方法，分析了所构建的不同组装结构相应的SERS信号，从中筛选建立了一种基于核酸适体-DNA连接的金纳米棒-金纳米粒子二元纳米组装结构的SERS传感器，并利用此SERS生物传感器对食品中OTA进行超灵敏、快速的检测应用。研究将高选择性、亲和力的OTA核酸适体与超灵敏SERS技术结合，突破局域场增强显著的组装体较优构型选择这个难题，通过优化碱基序列设计选择游离形态的核酸适体特异性识别OTA诱导的解组装的检测模式，减少空间位阻和识别难度并建立有效的传感方法。所述方法以核酸适体片段部分互补的DNA修饰到金纳米棒和金纳米粒子的表面构建两种纳米探针，在与适体互补杂交配对时可连接构建纳米组装结构，不同浓度赭曲霉毒素A标准溶液添加后靶分子与适体特异性结合可规律性抑制组装结构的生成，标记有拉曼信标分子的纳米组装结构SERS信号强度与组装结构的数量、大小相关，并筛选有效拉曼特征峰信息建立OTA定量模型。由此可利用所构建的适体传感器完成对含OTA这种真菌毒素食品样品的检测。本项目研究方法在液体环境中反应均匀，检测的灵敏度、特异性高，检测限可低至0.01ng/mL，此外仅需一步反应来测定、操作简单，为下一步研究结合便携式拉曼检测探头的小型传感器，用于现场真菌毒素检测提供了理论基础。研究成果可为具有我国自主知识产权的食品中真菌毒素快速检测装备的研发提供理论基础。