基于非对称修饰贵金属纳米粒子LSPR耦合的食品安全传感器的研制与应用

Food safety problem is a global issue. New problems are arising everyday. Consequently, the development of new detection approaches regarding these new issues is in urgent. This project is focusing on the development of novel detection approaches for food safety. The current cutting-edge techniques on LSPR coupling would be used to construct the detection platforms for food safety. Firstly, a novel method to synthesize asymmetrically functionalized noble metal nanoparticles would be presented. Around 95% of the surface area of the nanoparticles would be modified with molecules which would make the nanoparticles to be stable in the solution, while the other 5% surface area would be used for LSPR coupling and sensing. Due to the steric hindrance effect, these nanoparticles can only form dimers so that it can effectively avoid the uncontrollable nanoparticles aggregation during the LSPR coupling. After that, we will use this kind of asymmetrically functionalized nanoparticles to construct the detection platforms for the assay of nucleic acids, proteins and other chemicals involved in food safety. Eventually, the established platforms would be used for the analysis of the real samples regarding the food safety problems.

面对层出不穷的食品安全新问题，相应的分析与检测手段也需要不断更新。本项目以开发新型食品安全分析与检测方法为目的，将目前分析化学研究的前沿与热点内容-局域表面等离子共振（LSPR）纳米传感器应用到解决食品安全实际问题中去。为了解决基于LSPR耦合效应的纳米传感器在传感过程中粒子的不可控团聚与沉降问题，我们首先将开发一种新型的贵金属纳米粒子不对称修饰方法，该方法将在粒子表面约95%的区域修饰上一种纳米粒子稳定剂，从而有效提高粒子在溶液中的稳定性；而纳米粒子剩余约5%的区域则用于纳米耦合与传感。由于空间位阻效应，在纳米耦合过程中将只能形成纳米粒子二聚体，从而有效地解决了不可控团聚问题。接下来我们将用该方法修饰的纳米粒子构建一系列基于LSPR耦合效应的、针对特定食品安全检测对象的核酸传感器、蛋白质传感器以及小分子化学污染物传感器，并将其应用到食品安全复杂体系的分离分析中去。

基于胶体金聚集原理构建的比色传感器已经被广泛应用于医学诊断、食品安全检测及环境监测等领域的实际样品分析。然后，基于胶体金聚集原理构建的比色传感器普遍有两大缺点：一是稳定性差；二是检测灵敏度低。本项目采用非对称修饰的方法对纳米金进行修饰，从而控制了胶体金在传感过程中的聚集程度，解决了传统方法稳定性差及灵敏度低等缺点。本项目主要取得了以下几方面的进展：（1）报导了一种制备非对称修饰纳米金的新方法；（2）构建了一系列稳定性好、灵敏度高的食品安全可视化传感器。本项目共发表研究论文13篇，其中包括在本专业权威期刊J. Am. Chem. Soc., Nano Today, Small, 和Anal. Chem.等上发表相关研究成果。申请国家发明专利5项，其中有三项专利已经得到授权。