Opposite translocation of long and short oligomers through a nanopore.
Opposite translocation of long and short oligomers through a nanopore.
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长低聚物和短低聚物通过纳米孔的相反易位
DOI：
10.1103/physreve.87.062710
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
P. Reimann
中科院分区：
文献类型：
--
作者：
S. Getfert;T. Töws;P. Reimann
我们考虑拉长的圆柱形粒子，模拟例如DNA片段或纳米棒，同时它们在外部施加电压的作用下通过固态纳米孔进行移位。特别强调了粒子通过孔隙时遇到的伴随势能情况，这是由于超出小德拜长度的各种电流体效应的复杂相互作用。我们发现，对于相同直径和电荷密度的长短粒子(例如低聚物)，膜上的净势能差可能是相反的符号。因此，热噪声导致在相反方向上通过孔的偏向扩散。通过额外的膜栅电极，甚至可以控制发生这种输运反转的特定粒子长度。
We consider elongated cylindrical particles, modeling, e.g., DNA fragments or nanorods, while they translocate under the action of an externally applied voltage through a solid state nanopore. Particular emphasis is put on the concomitant potential energy landscape encountered by the particle on its passage through the pore due to the complex interplay of various electrohydrodynamic effects beyond the realm of small Debye lengths. We find that the net potential energy difference across the membrane may be of opposite sign for short and long particles of equal diameters and charge densities (e.g., oligomers). Thermal noise thus leads to biased diffusion through the pore in opposite directions. By means of an additional membrane gate electrode it is even possible to control the specific particle length at which this transport inversion occurs.