Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400030, P. R. China.
Chongqing School, University of Chinese Academy of Sciences, Chongqing 400714, P. R. China.
Anal Chem. 2022 Apr 12;94(14):5642-5650. doi: 10.1021/acs.analchem.1c05654. Epub 2022 Mar 30.
Single-molecule detection and characterization with nanopores is a powerful technique that does not require labeling. Multinanopore systems, especially double nanopores, have attracted wide attention and have been applied in many fields. However, theoretical studies of electrokinetic ion transport in nanopores mainly focus on single nanopores. In this paper, for the first time, a theoretical study of pH-regulated double-barreled nanopores is conducted using three-dimensional Poisson-Nernst-Planck equations and Navier-Stokes equations. Four ionic species and the surface chemistry on the walls of the nanopores are included. The results demonstrate that the properties of the bulk salt solution significantly affect nanopore conductivity and ion transport phenomena in nanopores. There are two ion-enriched zones and two ion-depleted zones in double-barreled nanopores. Due to the symmetry of the double-barreled nanopore structure and surface charge density, there is no ionic rectification effect in double-barreled nanopores. The ion selectivity is similar to that of conventional single pH-regulated nanopores.
利用纳米孔进行单分子检测和特性分析是一种无需标记的强大技术。多纳米孔系统，特别是双纳米孔，引起了广泛关注，并已应用于许多领域。然而，纳米孔中电动离子输运的理论研究主要集中在单纳米孔上。在本文中，首次使用三维泊松-纳维-斯托克斯方程和纳维-斯托克斯方程对 pH 调控双桶纳米孔进行了理论研究。包含了四种离子物种和纳米孔壁的表面化学。结果表明，本体盐溶液的性质显著影响纳米孔的电导率和纳米孔中离子输运现象。双桶纳米孔中有两个离子富集区和两个离子耗尽区。由于双桶纳米孔结构和表面电荷密度的对称性，双桶纳米孔中没有离子整流效应。离子选择性类似于传统的单 pH 调控纳米孔。
