Solid-state nanopore fabrication in LiCl by controlled dielectric breakdown
Solid-state nanopore fabrication in LiCl by controlled dielectric breakdown
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DOI：
10.1007/s10544-018-0281-9
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发表时间：
2018-04-21
影响因子：
2.8
通讯作者：
Shim, Jiwook
中科院分区：
文献类型：
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作者：
Bello, Julian;Shim, Jiwook
通过受控介电击穿(CDB)方法制备纳米孔提供了在盐溶液中直接制备亚纳米精度的固态纳米孔的机会。在陷阱辅助电流隧穿的驱动下，该方法利用介质材料中的局域缺陷或陷阱来隔离击穿点并在不到10分钟的时间内制造出一个单孔。在这里，我们提出了一种控制SiNx介电击穿的方法，其中纳米孔是在LiCl缓冲液中制备的，而不是传统的KCl缓冲液。在LiCl缓冲液中直接制备促进了均匀的、对称的、圆柱形的纳米孔结构，该结构是完全湿的，可以用于现场实验。我们已经证明，在氯化锂中制造减少了隔夜孔稳定的必要性，并允许在比在氯化钾中制造所需的时间短得多的时间内添加所需的分析物。这种方法产生的气孔可用于生物传感应用，包括检测双链DNA。DNA转位实验分别在氯化锂和氯化钾缓冲液中进行。在LiCl缓冲液中进行的实验与在相同浓度的KCl缓冲液中进行的实验相比，dsDNA转运持续时间增加了约2倍。当LiCl缓冲液的浓度增加3倍时，观察到与KCl相比，传输时间延长了10倍以上。
Nanopore fabrication via the controlled dielectric breakdown (CDB) method offers an opportunity to create solid-state nanopores directly in salt solution with sub-nanometer precision. Driven by trap assisted current tunneling, the method uses localized defects, or traps, in the dielectric material to isolate a breakdown point and fabricate a single pore in less than 10 minutes. Here we present an approach to controlled dielectric breakdown of SiNx in which the nanopore is fabricated in LiCl buffer instead of the traditional KCl buffer. Direct fabrication in LiCl buffer promotes a uniform, symmetric, cylindrical nanopore structure that is fully wet and can be used for experiments in situ. We have shown that fabrication in LiCl reduces the necessity for overnight pore stabilization and allows for the desired analyte to be added in significantly less time than it would take if fabrication was performed in KCl. Pores created by this approach can be used for biosensing applications, including the detection of double-stranded DNA. DNA translocation experiments were conducted in both LiCl and KCl buffer. Experiments conducted in LiCl buffer resulted in about a 2-fold increase in dsDNA transport duration when compared to experiments conducted in KCl buffer of the same concentration. An increase in transport duration of over 10-fold in comparison to KCl was observed when the concentration of the LiCl buffer was increased by a factor of 3.