Wireless Bipolar Nanopore Electrode for Single Small Molecule Detection
Wireless Bipolar Nanopore Electrode for Single Small Molecule Detection
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用于单个小分子检测的无线双极纳米孔电极
DOI：
10.1021/acs.analchem.7b00729
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发表时间：
2017-07-18
影响因子：
7.4
通讯作者：
Long, Yi-Tao
中科院分区：
文献类型：
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作者：
Gao, Rui;Ying, Yi-Lun;Long, Yi-Tao
基于固态纳米孔的技术已经成为用于各种单分子检测的有前途的策略。由于直径小于2nm的固态纳米孔的良好和快速制备的挑战，小分子检测难以通过现有的无标记纳米孔方法来解决。在这项工作中，我们首次提出了一种金属涂层的无线纳米孔电极（WNE），它提供了一种新的和普遍可用的检测方法，用于在单分子/离子水平上分析小分子和离子。在这里，银涂层的WNE被开发为原理验证模型，其通过监测增强的离子特征来实现在单个分子/离子水平上检测自生的H-2（已知的最小分子）和Ag+。在-800 mV的偏压下，WNE可以从一个峰电位信号中分辨出低至14个H-2分子和28个Ag+。有限元模拟表明，在WNE的孔处的H-2的产生导致离子电流的增强尖峰。作为概念验证实验，WNE进一步用于通过监测尖峰信号的频率来直接检测100 pM至100 nM的Hg 2+。这种新型的纳米电极为各种小分子/离子的检测，特别是氧化还原分析物的检测提供了一种全新的无标记，超灵敏，简单的检测机制。
Solid-state nanopore-based techniques have become a promising strategy for diverse single molecule detections. Owing to the challenge in well and rapid fabrication of solid-state nanopores with the diameter less than 2 nm, small molecule detection is hard to be addressed by existing label-free nanopore methods. In this work, we for the first time propose a metal-coated wireless nanopore electrode (WNE) which offers a novel and generally accessible detection method for analyzing small molecules and ions at the single molecule/ion level. Here, a silver-coated WNE is developed as a proof-of-principle model which achieves the detection the self-generated H-2, the smallest known molecule, and Ag+ at single molecule/ion level by monitoring the enhanced ionic signatures. Under a bias potential of -800 mV, the WNE could accomplish the distinction of as low as 14 H-2 molecules and 28 Ag+ from one spike signal. The finite element simulation is introduced to suggest that the generation of H-2 at the orifice of the WNE results in the enhanced spike of ionic current. As a proof-of-concept experiment, the WNE is further utilized to directly detect Hg2+ from 100 pM to 100 nM by monitoring the frequency of the spike signals. This novel nanoelectrode provides a brand new label-free, ultrasensitive, and simple detection mechanism for various small molecules/ions detection, especially for redox analytes.