State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
Analyst. 2019 Oct 7;144(20):6108-6117. doi: 10.1039/c9an01338e.
There is an increasing urge to investigate facile solutions for monitoring biotoxins, which are a major concern in both the food safety and the anti-terrorism fields. Current techniques, such as immunochromatographic tests (ICT), enzyme-linked immunosorbent assay (ELISA) and mass spectrometry, are still insufficient to satisfy the needs for fast, label-free, and ultra-sensitive detection. Herein, a single-molecular, label-free detection method based on atomic force microscopy was employed to solve the abovementioned problem via a photo-induced force spectrum; typically, three important biotoxins, i.e. abrin toxin (ABR), ricin toxin (RT) and Clostridium perfringens exotoxin (ETX), were used for the demonstration of single molecule detection. The photo-induced force spectrum could be successfully obtained for each of the single protein particles with molecular weights down to 30 kDa. Furthermore, principal component analysis (PCA) was applied for each protein, resulting in a standard PCA identification database. Then, individual components in a mixture of these toxin proteins were well distinguished from each other via matching with the as-built database. Using this strategy, PiFM not only could be used as a powerful tool for single protein detection, but could also be used as a potential tool in protein structural analysis.
人们越来越希望找到简便的方法来监测生物毒素，生物毒素是食品安全和反恐领域的主要关注点。目前的技术，如免疫层析试验（ICT）、酶联免疫吸附试验（ELISA）和质谱法，仍然不足以满足快速、无标记和超高灵敏度检测的需求。在此，我们采用基于原子力显微镜的单分子无标记检测方法，通过光致力谱解决了上述问题；通常，我们使用三种重要的生物毒素，即相思豆毒素（ABR）、蓖麻毒素（RT）和产气荚膜梭菌外毒素（ETX），来演示单分子检测。成功地获得了分子量低至 30 kDa 的每个单蛋白颗粒的光致力谱。此外，我们对每种蛋白质都进行了主成分分析（PCA），得到了一个标准的 PCA 识别数据库。然后，通过与已建立的数据库进行匹配，可以很好地区分混合物中各毒素蛋白的个别成分。通过这种策略，PiFM 不仅可以作为一种强大的单蛋白检测工具，还可以作为蛋白质结构分析的潜在工具。
