DNA sequence motifs for structure-specific recognition and separation of carbon nanotubes
DNA sequence motifs for structure-specific recognition and separation of carbon nanotubes
复制标题
DOI：
10.1038/nature08116
复制
发表时间：
2009-07-09
期刊：
影响因子：
64.8
通讯作者：
Zheng, Ming
中科院分区：
文献类型：
--
作者：
Tu, Xiaomin;Manohar, Suresh;Zheng, Ming
单壁碳纳米管(SWNTs)是一类具有相同圆柱形但手性不同的分子。许多单壁碳纳米管的基础研究和技术应用(2)需要一组具有相同手性的管子，这是目前的合成方法无法提供的。近年来，单壁碳纳米管的分选问题引起了相当大的关注。到目前为止，紧张的努力主要集中在分拣问题的一个较弱的版本上，并产生了解决方案：金属/半导体分离(3，4)。从合成的单壁碳纳米管混合物中提纯同一电子类型的每一个单一手性物种的系统和一般方法是非常可取的，但这项任务迄今已被证明是无法克服的。在这里，我们报告了这样一种方法，它允许从合成混合物中提纯所有12个主要的单手性半导体物种，并获得足够的产率，用于基础研究和应用开发。我们已经设计了一个大小类似于10(60)的DNA文库的有效搜索，并已经鉴定了20多个短DNA序列，每个短DNA序列都识别并能够从合成混合物中对特定的纳米管物种进行层析纯化。识别序列呈现出周期性的嘌呤-嘧啶模式，这种模式可以通过氢键形成二维片，并选择性地在纳米管上折叠成有序的三维桶。我们认为有序的二维片和三维筒为观察到的单壁碳纳米管的DNA识别提供了结构基础。
Single-walled carbon nanotubes (SWNTs) are a family of molecules that have the same cylindrical shape but different chiralities(1). Many fundamental studies and technological applications(2) of SWNTs require a population of tubes with identical chirality that current syntheses cannot provide. The SWNT sorting problem-that is, separation of a synthetic mixture of tubes into individual single-chirality components-has attracted considerable attention in recent years. Intense efforts so far have focused largely on, and resulted in solutions for, a weaker version of the sorting problem: metal/semiconductor separation(3,4). A systematic and general method to purify each and every single-chirality species of the same electronic type from the synthetic mixture of SWNTs is highly desirable, but the task has proven to be insurmountable to date. Here we report such a method, which allows purification of all 12 major single-chirality semiconducting species from a synthetic mixture, with sufficient yield for both fundamental studies and application development. We have designed an effective search of a DNA library of similar to 10(60) in size, and have identified more than 20 short DNA sequences, each of which recognizes and enables chromatographic purification of a particular nanotube species from the synthetic mixture. Recognition sequences exhibit a periodic purine-pyrimidines pattern, which can undergo hydrogen-bonding to form a two-dimensional sheet, and fold selectively on nanotubes into a well-ordered three-dimensional barrel. We propose that the ordered two-dimensional sheet and three-dimensional barrel provide the structural basis for the observed DNA recognition of SWNTs.