MoS2纳米孔中离子液体-水电解质界面上的分子传输。,ACS Applied Materials & Interfaces

当前位置： X-MOL 学术 › ACS Appl. Mater. Interfaces › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

MoS2纳米孔中离子液体-水电解质界面上的分子传输。
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2020-05-12 , DOI: 10.1021/acsami.0c04523
Manish Shankla ₁ , Aleksei Aksimentiev ₁

Affiliation

通过使用生物酶使DNA穿过工程化的生物纳米孔，同时记录流过纳米孔的离子流，已实现了DNA的纳米孔测序。使用固态纳米孔来实现类似概念的努力已经遇到了几个技术挑战，其中一个挑战是DNA易位的高速性，另一个挑战是各个核苷酸之间的低离子电流对比度。解决这两个问题的有前途的途径是使用离子液体来减缓DNA迁移和MoS _2中的微小纳米孔膜以区分单个核苷酸。实现这些技术进步的物理机制仍然难以捉摸。在这里，我们描述了在有和没有MoS _2的情况下，离子和DNA通过离子液体/水电解质界面的传输特性纳米孔，使用全原子分子动力学方法。我们发现离子液体和水性电解质的部分可混溶性大大改变了纳米孔易位过程的物理性质。因此，两相的界面产生600 mV的接触电势，离子电流受离子液体分子通过水溶液相的运动的控制，并且DNA核苷酸表现出优先分配到电解质水溶液中的能力，这导致自发的在没有外部电压偏置的情况下将DNA聚合物从离子液体传输到水溶液室。两相纳米孔系统的复杂物理学为扩展纳米孔传感平台的功能提供了许多机会。

"点击查看英文标题和摘要"

Molecular Transport across the Ionic Liquid-Aqueous Electrolyte Interface in a MoS2 Nanopore.

Nanopore sequencing of DNA has been enabled by the use of a biological enzyme to thread DNA through an engineered biological nanopore while recording the ionic current flowing through the nanopore. Efforts to realize a similar concept using a solid-state nanopore have been met with several technical challenges, one of which is the high speed of DNA translocation and the other the low ionic current contrast among individual nucleotides. A promising avenue to addressing both problems is using an ionic liquid to slow DNA translocation and a tiny nanopore in the MoS₂ membrane to distinguish individual nucleotides. The physical mechanisms enabling these technical advances have remained elusive. Here, we characterize the ion and DNA transport through the ionic liquid/aqueous electrolyte interface, with and without a MoS₂ nanopore, using the all-atom molecular dynamics method. We find that the partial miscibility of the ionic liquid and the aqueous electrolyte considerably alters the physics of the nanopore translocation process. Thus, the interface of the two phases generates a contact potential of 600 mV, the ionic current is dominated by the motion of ionic liquid molecules through the aqueous solution phase, and the DNA nucleotides exhibit preferential partitioning into the aqueous electrolyte, which leads to spontaneous transport of DNA polymers from the ionic liquid to the aqueous solution compartment in the absence of external voltage bias. The complex physics of the two-phase nanopore system offers a multitude of opportunities for extending the functionality of nanopore-sensing platforms.

更新日期：2020-05-12

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南