Nature Nanotechnology：双螺旋结构导电性堪比石墨圈 |
| 来源：Nature Nanotechnology 作者：无 发布时间：2008-04-07 |
研究人员在2月在线出版的《自然—纳米技术》（Nature Nanotechnology）上报告，将单个DNA分子的导电性与一个纳米尺度的电路连接在一起，就可以测量这个DNA分子的导电能力。新结果显示，以碱基对为基础的双螺旋结构的导电性可简单地与同样大小的石墨圈相提并论。 Colin Nuckolls和Jacqueline Barton 带领的研究小组制作了一个微型电路，其中一段是单壁碳纳米管。在纳米管间开一个小槽，电路被打开，电流就不再流过电路。然而，当这个小口被一个DNA分子连接上时，不仅电路恢复了导电能力，而且也可测出DNA的电学性质。实验还表明，DNA中即使只有一个碱基对错位了，整个电路的导电能力也大大下降。 如果用一段酶切断作为桥梁的DNA，那么整个电路的电流也被中断了。这表明DNA采纳的是自然形态，而不是被电路设备所扭曲的形态。因此可以推测，电路的导电性不是由测量技术形成的人工产品。 原始出处： （Nature Nanotechnology），doi:10.1038/nnano.2008.4，Xuefeng Guo，Colin Nuckolls Conductivity of a single DNA duplex bridging a carbon nanotube gapXuefeng Guo1,2, Alon A. Gorodetsky3, James Hone2,4, Jacqueline K. Barton3 & Colin Nuckolls1,2 AbstractWe describe a general method to integrate DNA strands between single-walled carbon nanotube electrodes and to measure their electrical properties. We modified DNA sequences with amines on either the 5' terminus or both the 3' and 5' termini and coupled these to the single-walled carbon nanotube electrodes through amide linkages, enabling the electrical properties of complementary and mismatched strands to be measured. Well-matched duplex DNA in the gap between the electrodes exhibits a resistance on the order of 1 M |
. A single GT or CA mismatch in a DNA 15-mer increases the resistance of the duplex 
300-fold relative to a well-matched one. Certain DNA sequences oriented within this gap are substrates for Alu I, a blunt end restriction enzyme. This enzyme cuts the DNA and eliminates the conductive path, supporting the supposition that the DNA is in its native conformation when bridging the ends of the single-walled carbon nanotubes.| 最新评论： |