The aggregation of nanoparticles is the key factor to form hot spots for the flocculation-enhanced Raman spectroscopy (FLERS) method. However, the structure of flocculation is still not clear. It is therefore necessary to explore and analyze the aggregation process of nanoparticles more carefully, so as to realize a better application of FLERS. Here, we report the application of in situ liquid cell transmission electron microscopy (TEM) combined with an in situ high-speed camera to analyze the particle behaviors. The results showed that flocculation can exist stably and the gap between the nanoparticles in the flocculation always remained at 7–9 nm, which ensured the high stability and sensitivity of the FLERS method. We successfully applied FLERS to the in situ noninvasive probing of cupping effect substances. The results indicated the scientific principle behind the traditional Chinese medicine method to some extent, which thus provides a new and effective method for the in situ dynamic monitoring of biological systems.

中文翻译：

---

洞察超灵敏和高稳定性絮凝增强拉曼光谱在原位无创探测拔罐效应物质

纳米粒子的聚集是絮凝增强拉曼光谱（FLERS）方法形成热点的关键因素。然而，絮凝的结构仍不清楚。因此，有必要更仔细地探索和分析纳米粒子的聚集过程，以实现FLERS的更好应用。在这里，我们报告了原位液体细胞透射电子显微镜 (TEM) 与原位高速相机相结合来分析粒子行为的应用。结果表明，絮凝可以稳定存在，絮凝中纳米粒子之间的间隙始终保持在7-9 nm，保证了FLERS方法的高稳定性和灵敏度。我们成功地将 FLERS 应用于原位无创探测拔罐效应物质。研究结果在一定程度上表明了中医方法背后的科学原理，从而为生物系统的原位动态监测提供了一种新的有效方法。