Lee Jung Soo, Oviedo Juan Pablo, Bandara Yapa Mudiyanselage Nuwan Dhananjaya Yapa, Peng Xin, Xia Longsheng, Wang Qingxiao, Garcia Kevin, Wang Jinguo, Kim Min Jun, Kim Moon Jae
Applied Science Program, Lyle School of Engineering, Southern Methodist University, Dallas, TX, USA.
Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, TX, USA.
Electrophoresis. 2021 Apr;42(7-8):991-1002. doi: 10.1002/elps.202000356. Epub 2021 Mar 3.
Accomplishing slow translocation speed with high sensitivity has been the most critical mission for solid-state nanopore (SSN) device to electrically detect nucleobases in ssDNA. In this study, a method to detect nucleobases of ssDNA using a 2D SSN is introduced by considerably reducing the translocation speed and effectively increasing its sensitivity. The ultra-thin titanium dioxide coated hexagonal boron nitride nanopore was fabricated, along with an ionic-liquid 1-butyl-3-methylimidazolium hexafluorophosphate/2.0 M KCl aqueous (cis/trans) interface, for increasing both the spatial and the temporal resolutions. As the ssDNA molecules entered the nanopore, a brief surge of electrical conductivity occurred, which was followed by multiple resistive pulses from nucleobases during the translocation of ssDNA and another brief current surge flagging the exit of the molecule. The continuous detection of nucleobases using a 2D SSN device is a novel achievement: the water molecules bound to ssDNA increased the molecular conductivity and amplified electrical signals during the translocation. Along with the experiment, computational simulations using COMSOL Multiphysics are presented to explain the pivotal role of water molecules bound to ssDNA to detect nucleobases using a 2D SSN.
在固态纳米孔（SSN）装置中，以高灵敏度实现缓慢的转运速度一直是电检测单链DNA（ssDNA）中核碱基的最关键任务。在本研究中，通过大幅降低转运速度并有效提高其灵敏度，引入了一种使用二维SSN检测ssDNA核碱基的方法。制备了超薄二氧化钛涂层的六方氮化硼纳米孔，以及离子液体1-丁基-3-甲基咪唑六氟磷酸盐/2.0 M氯化钾水溶液（顺式/反式）界面，以提高空间和时间分辨率。当ssDNA分子进入纳米孔时，会出现短暂的电导率激增，随后在ssDNA转运过程中来自核碱基的多个电阻脉冲出现，另一个短暂的电流激增标志着分子的退出。使用二维SSN装置连续检测核碱基是一项新成就：与ssDNA结合的水分子增加了分子电导率，并在转运过程中放大了电信号。除了实验，还展示了使用COMSOL Multiphysics进行的计算模拟，以解释与ssDNA结合的水分子在使用二维SSN检测核碱基中的关键作用。
