Wang Ying, Yao Fujun, Kang Xiao-feng
Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University , Xi'an 710069, P. R. China.
Anal Chem. 2015 Oct 6;87(19):9991-7. doi: 10.1021/acs.analchem.5b02611. Epub 2015 Sep 30.
Nanopore technology, as the simplest and most inexpensive single-molecule tool, is being intensively developed. In nanopore stochastic sensing, KCl and NaCl have traditionally been employed as pore-filled electrolytes for recording the change of ion conductance in nanopores triggered by analyte translocation through the pore. However, some challenges limit its further advance. Here we used tetramethylammonium (TMA) chloride, instead of KCl, as a novel analysis system for nanopores. Some unique nanopore characteristics were observed: (1) The stability of the planar lipid bilayer for embedding the protein pores was elevated at least 6 times. (2) The TMA-Cl system could effectively reduce the noise of single-channel recording. (3) It was easy to control the insertion of protein pores into the lipid bilayer, and the formed single nanopore could last for a sufficiently long time. (4) TMA-Cl could be used as a DNA speed bump in the nanopore to slow DNA translocation speed. (5) The capacity of the nanopore capture of DNA (capture rate) increased significantly and simultaneously increased the translocation time of DNA in the pore. (6) The TMA-filled nanopore could discriminate between various polynucleotides.
纳米孔技术作为最简单且最廉价的单分子工具，正在被大力研发。在纳米孔随机传感中，传统上一直使用氯化钾（KCl）和氯化钠（NaCl）作为填充在孔中的电解质，以记录由于分析物通过孔的转运而引发的纳米孔中离子电导的变化。然而，一些挑战限制了其进一步发展。在此，我们使用氯化四甲基铵（TMA）而非KCl作为纳米孔的新型分析系统。观察到了一些独特的纳米孔特性：（1）用于嵌入蛋白质孔的平面脂质双层的稳定性提高了至少6倍。（2）TMA-Cl系统能够有效降低单通道记录的噪声。（3）易于控制蛋白质孔插入脂质双层，并且形成的单个纳米孔能够持续足够长的时间。（4）TMA-Cl可以用作纳米孔中的DNA减速带，以减慢DNA的转运速度。（5）纳米孔捕获DNA的能力（捕获率）显著提高，同时增加了DNA在孔中的转运时间。（6）填充TMA的纳米孔能够区分各种多核苷酸。
