Department of Physics, Clarkson University, Potsdam, NY 13699, USA.
Nanotechnology. 2012 Jun 29;23(25):255501. doi: 10.1088/0957-4484/23/25/255501. Epub 2012 May 31.
We have studied single-stranded DNA translocation through a semiconductor membrane consisting of doped p and n layers of Si forming a p-n-junction. Using Brownian dynamics simulations of the biomolecule in the self-consistent membrane-electrolyte potential obtained from the Poisson-Nernst-Planck model, we show that while polymer length is extended more than when its motion is constricted only by the physical confinement of the nanopore. The biomolecule elongation is particularly dramatic on the n-side of the membrane where the lateral membrane electric field restricts (focuses) the biomolecule motion more than on the p-side. The latter effect makes our membrane a solid-state analog of the α-hemolysin biochannel. The results indicate that the tunable local electric field inside the membrane can effectively control dynamics of a DNA in the channel to either momentarily trap, slow down or allow the biomolecule to translocate at will.
我们研究了通过由掺杂的 p 和 n 层 Si 组成的半导体膜进行单链 DNA 易位，这些 Si 形成了 p-n 结。使用布朗动力学模拟，在自洽的膜-电解质势中模拟生物分子，该势由泊松-纳恩斯-普朗克模型获得，我们表明，当聚合物长度比仅受纳米孔物理限制时更长。在膜的 n 侧，生物分子的伸长特别明显，那里的横向膜电场比在 p 侧更限制（聚焦）生物分子的运动。后一种效应使得我们的膜成为 α-溶血素生物通道的固态类似物。结果表明，膜内可调谐的局部电场可以有效地控制通道中 DNA 的动力学，从而可以暂时捕获、减慢或允许生物分子随意易位。
