Lyu Min, Li Cheng, Liu Yanzhao, Li Yan, Zheng Ming
Beijing National Laboratory for Molecular Science, Key Laboratory for the Physics and Chemistry of Nanodevices, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, United States.
Sci Adv. 2025 Jul 11;11(28):eadx3958. doi: 10.1126/sciadv.adx3958.
Sorting single-wall carbon nanotubes (SWCNTs) by chirality/handedness is of substantial scientific and technological importance. Existing sorting methods often lack simplicity, reproducibility and scalability. Here, we demonstrate a salt-driven SWCNT sorting mechanism that addresses these challenges. Various polyethylene glycol (PEG)/salt aqueous two-phase systems effectively modulate the top-phase partitioning of DNA-wrapped SWCNTs (DNA-SWCNTs) across a broad range of hydrophobicities, with cation composition markedly affecting top-phase partitioning in the order NH > K > Li > Na closely resembles the well-documented Hofmeister series. We designed PEG/salt systems with defined [K]:[Na] cation ratios to precisely regulate SWCNT partitioning, enabling one-step top-extraction of multiple single-chirality SWCNTs. The cation ratio parameter, determined in small-scale experiments, remains effective at scales 200 times larger, allowing one-step, milligram-scale separation of (-) (6,5) with record-high enantiomeric purity. In addition, we develop a salt-switching multistage bottom-extraction strategy to isolate (+) (6,5) enantiomer. Our method uses simple salts to provide an easy-to-implement, high-precision, scale-invariant, and cost-effective platform for routine SWCNT chirality sorting.
按手性对单壁碳纳米管(SWCNT)进行分类具有重大的科学和技术意义。现有的分类方法往往缺乏简便性、可重复性和可扩展性。在此,我们展示了一种盐驱动的SWCNT分类机制,该机制解决了这些挑战。各种聚乙二醇(PEG)/盐水两相系统能在广泛的疏水性范围内有效调节DNA包裹的SWCNT(DNA-SWCNT)在顶相中的分配情况,并发现阳离子组成对顶相分配有显著影响,其顺序为NH>K>Li>Na, 此顺序与有充分记录的霍夫迈斯特序列非常相似. 我们设计了具有特定[K]:[Na]阳离子比例(即阳离子比)的PEG/盐系统,以精确调节SWCNT的分配情况,从而能够一步从顶相提取多种单一手性的SWCNT. 在小规模实验中确定的阳离子比参数在规模大200倍的实验中仍然有效,从而能够以创纪录的高对映体纯度一步分离毫克级的(-)(6,5)单壁碳纳米管。此外,我们还开发了一种盐切换多级底相提取策略来分离(+)(6,5)对映体。我们的方法使用简单的盐,为常规的SWCNT手性分类提供了一个易于实施、高精度、规模不变且经济高效的平台。