已有 7093 次阅读 2009-8-11 14:56 |个人分类:科研论文|系统分类:科研笔记


近来,Nature报道了用DAN纯化纳米管的方法。(Nature 2009, 460, 250-253 )


       碳纳米管韧性高、导电性强、场发射性能优良,兼具金属性和半导体性,有“超级纤维”之称。碳纳米管在纳米电子器件方面非常有应用前景。但是,迄今所制造出的碳纳米管基本是金属和半导体管的混合物,它们具有不同直径和手性。要使纳米管投入实际应用,比如应用在电子系统中,很重要的一点就是要能够对每种纳米管进行纯化。杜邦公司(DuPont Central Research and Development)的Xiaomin Tu,Ming Zheng 和宾夕法尼亚州里海大学(Lehigh University)的Suresh Manohar, Anand Jagota等人将DNA用于这项工作,并取得了很好的效果。

Rice University, R. Bruce Weisman 对此评论:“This is a very impressive study that reports the most selective method yet found for isolating specific structural forms of SWNTs from mixed samples.”


Single-walled carbon nanotubes (SWNTs) are a family of molecules that have the same cylindrical shape but different chiralities. Many fundamental studies and technological applications 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. 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 approx1060 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.





发表评论 评论 (3 个评论)


Archiver|手机版|科学网 ( 京ICP备07017567号-12 )

GMT+8, 2021-4-14 00:33

Powered by

Copyright © 2007- 中国科学报社