DNA-assisted dispersion and separation of carbon nanotubes
DNA-assisted dispersion and separation of carbon nanotubes
复制标题
DOI：
10.1038/nmat877
复制
发表时间：
2003-05-01
期刊：
影响因子：
41.2
通讯作者：
Tassi, NG
中科院分区：
文献类型：
--
作者：
Zheng, M;Jagota, A;Tassi, NG
碳纳米管是具有不同直径和手性的人造一维碳晶体。由于其卓越的机械和电气性能，它们被提出了许多潜在的应用。然而，它们在水和非水溶液中的多分散性和溶解度差给它们的分离和组装带来了相当大的挑战，而这是许多应用所需要的。在这里，我们报告了 DNA 辅助碳纳米管分散和分离的发现。在单链 DNA (ssDNA) 存在的情况下，通过超声处理，成束的单壁碳纳米管可以有效地分散在水中。光学吸收和荧光光谱以及原子力显微镜测量为单独分散的碳纳米管提供了证据。分子模型表明，单链 DNA 可以通过 π 堆积与碳纳米管结合，从而形成螺旋状包裹在表面。单链 DNA 与碳纳米管的结合自由能可与两个纳米管的结合自由能相媲美。我们还证明，DNA 包被的碳纳米管可以通过离子交换色谱法分离成具有不同电子结构的组分。这一发现将生物学中的一个中心分子与一种技术上非常重要的纳米材料联系起来，并为基于碳纳米管的生物技术应用打开了大门。
Carbon nanotubes are man-made one-dimensional carbon crystals with different diameters and chiralities. Owing to their superb mechanical and electrical properties, many potential applications have been proposed for them. However, polydispersity and poor solubility in both aqueous and non-aqueous solution impose a considerable challenge for their separation and assembly, which is required for many applications. Here we report our finding of DNA-assisted dispersion and separation of carbon nanotubes. Bundled single-walled carbon nanotubes are effectively dispersed in water by their sonication in the presence of single-stranded DNA (ssDNA). Optical absorption and fluorescence spectroscopy and atomic force microscopy measurements provide evidence for individually dispersed carbon nanotubes. Molecular modelling suggests that ssDNA can bind to carbon nanotubes through pi-stacking, resulting in helical wrapping to the surface. The binding free energy of ssDNA to carbon nanotubes rivals that of two nanotubes for each other. We also demonstrate that DNA-coated carbon nanotubes can be separated into fractions with different electronic structures by ion-exchange chromatography. This finding links one of the central molecules in biology to a technologically very important nanomaterial, and opens the door to carbon-nanotube-based applications in biotechnology.