Lv Wenping, Liu Shengju, Li Xin, Wu Ren'an
CAS Key Lab of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Dalian, P. R. China.
Electrophoresis. 2014 Apr;35(8):1144-51. doi: 10.1002/elps.201300501. Epub 2014 Mar 5.
Graphene nanopore has been promising the ultra-high resolution for DNA sequencing due to the atomic thickness and excellent electronic properties of the graphene monolayer. The dynamical translocation phenomena and/or behaviors underneath the blocked ionic current, however, have not been well unveiled to date for the translocation of DNA electrophoretically through a graphene nanopore. In this report, the assessment on the sensitivity of ionic current to instantaneous statuses of DNA in a 2.4 nm graphene nanopore was carried out based on the all-atom molecular dynamics simulations. By filtering out the thermal noise of ionic current, the instantaneous conformational variations of DNA in a graphene nanopore have been unveiled from the fluctuations of ionic current, because of the spatial blockage effect of DNA against ionic current. Interestingly, the neighborhood effect of DNA against ionic current was also observed within a distance of 1.5 nm nearby the graphene nanopore, suggesting the further precise control for DNA translocation through a graphene nanopore in gene sequencing. Moreover, the sensitivity of the blocked ionic current toward the instantaneous conformations of DNA in a graphene nanopore demonstrates the great potential of graphene nanopores in the dynamics analysis of single molecules.
由于石墨烯单原子层的原子厚度和优异的电学性质，石墨烯纳米孔在DNA测序方面具有超高分辨率的潜力。然而，迄今为止，对于DNA通过石墨烯纳米孔进行电泳转运时，阻塞离子电流下的动态转运现象和/或行为尚未得到充分揭示。在本报告中，基于全原子分子动力学模拟，对2.4纳米石墨烯纳米孔中离子电流对DNA瞬时状态的敏感性进行了评估。通过滤除离子电流的热噪声，由于DNA对离子电流的空间阻塞效应，从离子电流的波动中揭示了石墨烯纳米孔中DNA的瞬时构象变化。有趣的是，在石墨烯纳米孔附近1.5纳米的距离内还观察到了DNA对离子电流的邻域效应，这表明在基因测序中对DNA通过石墨烯纳米孔的转运可以进行更精确的控制。此外，石墨烯纳米孔中阻塞离子电流对DNA瞬时构象的敏感性证明了石墨烯纳米孔在单分子动力学分析中的巨大潜力。
