Zhao Yanlu, Choi Sungmoon, Yu Junhua
Department of Chemistry Education, Seoul National University, Seoul 08826, Republic of Korea.
J Phys Chem Lett. 2020 Aug 20;11(16):6867-6872. doi: 10.1021/acs.jpclett.0c01950. Epub 2020 Aug 10.
Characterizing nanocages in macromolecules is one of the keys to understanding various biological activities and further utilizing nanocages for novel materials synthesis. However, fast and straightforward detection of the nanocage size remains challenging. Here, we present a new approach to detect the diameter of a nanocage by Förster resonance energy transfer (FRET) of luminescent silver nanodot pairs with reverse micelles as a model. Silver nanodot FRET pairs can be generated from a single silver nanodot species with critical energy transfer distances, , of 4.8-6.5 nm. We have applied this approach to clarify the size variation of the water nanocage in nonionic surfactant Triton X-100-based reverse micelles. FRET efficiency decreases as more water is added, indicating that the size of the reverse micelles continuously expands with water content. The silver element in the nanocage also enhances the visualization of the nanocage under cryo-TEM imaging. The diameter of the water nanocage measured with the above approach is consistent with that obtained by cryo-TEM, demonstrating that the FRET measurement of silver nanodots can be a fast and accurate tool to detect nanocage dimensions. The above demonstration allows us to apply our strategy to other protein-based nanocages.
表征大分子中的纳米笼是理解各种生物活性以及进一步将纳米笼用于新型材料合成的关键之一。然而，快速直接地检测纳米笼的尺寸仍然具有挑战性。在此，我们提出了一种新方法，以反胶束为模型，通过发光银纳米点对的Förster共振能量转移（FRET）来检测纳米笼的直径。银纳米点FRET对可以由具有4.8 - 6.5 nm的临界能量转移距离的单一银纳米点物种产生。我们已应用此方法来阐明基于非离子表面活性剂Triton X - 100的反胶束中水纳米笼的尺寸变化。随着加入更多的水，FRET效率降低，这表明反胶束的尺寸随着含水量的增加而持续扩大。纳米笼中的银元素在低温透射电子显微镜成像下也增强了纳米笼的可视化效果。用上述方法测量的水纳米笼的直径与通过低温透射电子显微镜获得的直径一致，这表明银纳米点的FRET测量可以成为检测纳米笼尺寸的快速且准确的工具。上述论证使我们能够将我们的策略应用于其他基于蛋白质的纳米笼。
