Li Yinong, Wen Yawei, Beltrán Leticia C, Zhu Li, Tian Shishan, Liu Jialong, Zhou Xuan, Chen Piaoyi, Egelman Edward H, Zheng Ming, Lin Zhiwei
South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA.
Sci Adv. 2025 Apr 4;11(14):eadt9844. doi: 10.1126/sciadv.adt9844. Epub 2025 Apr 2.
DNA has demonstrated the abilities to differentiate single-wall carbon nanotubes (SWCNTs) with various chiralities and manipulate their analyte sensing properties. However, the fundamental mechanisms underlying these remarkable abilities remain unclear due to the lack of high-resolution determination of DNA structures on SWCNTs. Here, we combine atomic force microscopy and single-particle cryo-electron microscopy to determine DNA structures on five different types of single-chirality SWCNTs, achieving unprecedented subnanometer resolution. This resolution enables the direct observation of left-handed helical DNA structures with pitches ranging from 1.59 to 2.20 nm, depending on the DNA sequence and nanotube chirality. These findings provide structural insights into the mechanisms by which DNA differentiates the chirality of SWCNTs, and governs the sensitivity, dynamic response range, and analyte differentiability of SWCNT sensors. We propose a non-Watson-Crick hydrogen-bonding network model, which not only accounts for the observed ordered DNA structures but also facilitates the design of DNA sequences for targeted SWCNT purification and desired SWCNT sensor performance.
DNA已展现出区分具有不同手性的单壁碳纳米管（SWCNT）以及操控其分析物传感特性的能力。然而，由于缺乏对SWCNT上DNA结构的高分辨率测定，这些非凡能力背后的基本机制仍不清楚。在此，我们结合原子力显微镜和单颗粒冷冻电子显微镜来确定五种不同类型的单手性SWCNT上的DNA结构，实现了前所未有的亚纳米分辨率。这种分辨率能够直接观察到左手螺旋DNA结构，其螺距范围为1.59至2.20纳米，具体取决于DNA序列和纳米管手性。这些发现为DNA区分SWCNT手性以及控制SWCNT传感器的灵敏度、动态响应范围和分析物可区分性的机制提供了结构上的见解。我们提出了一种非沃森-克里克氢键网络模型，该模型不仅解释了观察到的有序DNA结构，还便于设计用于靶向SWCNT纯化和所需SWCNT传感器性能的DNA序列。
