Water-Compression Gating of Nanopore Transport.
Water-Compression Gating of Nanopore Transport.
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DOI：
10.1103/physrevlett.120.268101
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发表时间：
2018-06-29
影响因子：
8.6
通讯作者：
Aksimentiev A
中科院分区：
文献类型：
--
作者：
Wilson J;Aksimentiev A
生物分子的电场驱动运动是许多分析方法所必需的过程，特别是对于纳米孔感测，其中纳米孔离子电流的瞬时降低指示生物分子通过纳米孔。但是在任何分子可以通过纳米孔进行检测之前，分子必须首先从溶液进入纳米孔。以前，发现纳米孔的捕获速率随着所施加电场的强度而增加。在这里，我们从理论上表明，在石墨烯膜中的窄孔的情况下，增加电场的强度不仅可以降低捕获速率，还可以将生物分子从纳米孔中排斥出来。由于强电场使纳米孔附近和纳米孔内的水极化，场的高梯度也产生压缩水的强介电泳力。由急剧的水密度梯度引起的压力差产生了一种流体静力，将DNA或蛋白质从纳米孔中排斥出来，在某些条件下阻止了它们的捕获。我们表明，这种局部压缩的流体可以调节生物分子的运输通过纳米级通道的情况下，物理门和排序蛋白质根据其磷酸化状态。
Electric field-driven motion of biomolecules is a process essential to many analytics methods, in particular, to nanopore sensing, where a transient reduction of nanopore ionic current indicates the passage of a biomolecule through the nanopore. But before any molecule can be examined by a nanopore, the molecule must first enter the nanopore from the solution. Previously, the rate of capture by a nanopore was found to increase with the strength of the applied electric field. Here, we theoretically show that, in the case of narrow pores in graphene membranes, increasing the strength of the electric field can not only decrease the rate of capture but also repel biomolecules from the nanopore. As the strong electric field polarizes water near and within the nanopore, the high gradient of the field also produces a strong dielectrophoretic force that compresses the water. The pressure difference caused by the sharp water density gradient produces a hydrostatic force that repels DNA or proteins from the nanopore, preventing, in certain conditions, their capture. We show that such local compression of fluid can regulate the transport of biomolecules through nanoscale passages in the absence of physical gates and sort proteins according to their phosphorylated states.