Crucial Role of Out-of-Pore Resistance on Temporal Response of Ionic Current in Nanopore Sensors
Crucial Role of Out-of-Pore Resistance on Temporal Response of Ionic Current in Nanopore Sensors
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DOI：
10.1021/acssensors.0c00014
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发表时间：
2020-06-26
期刊：
影响因子：
8.9
通讯作者：
Taniguchi, Masateru
中科院分区：
文献类型：
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作者：
Kishimoto, Shohei;Murayama, Sanae;Taniguchi, Masateru
我们研究了固态纳米孔传感器中离子电流的时间分辨率。当我们通过膜上的集成微流体通道向孔串联施加更大的外部电阻时，发现在单纳米颗粒移位时观察到的电阻脉冲变得更钝。发现即使当孔外电阻比纳米孔处的电阻小一个数量级以上时也会发生这种情况，这可以被理解为在水接触的薄微电极处的充电/放电的主要贡献，以延迟离子电流对通过感测区的快速移动物体的离子阻塞的响应。最重要的是，我们的结果预测优于12 ns的时间分辨率，无论纳米孔的大小，通过优化膜电容和外部电阻，承诺高速单分子测序的离子电流在10（6）碱基/秒。
We investigated the temporal resolution of ionic current in solid-state nanopore sensors. Resistive pulses observed upon translocation of single-nanoparticles were found to become blunter as we imposed larger external resistance in series to the pore via the integrated microfluidic channels on the membrane. This was found to occur even when the out-of-pore resistance is more than an order of magnitude smaller than that at the nanopore, which can be understood as a predominant contribution of charging/discharging at the water-touching thin dielectrics to retard the response of the ionic current against ion blockage by a fast-moving object through the sensing zone. Most importantly, our results predict a time resolution of better than 12 ns, irrespective of the nanopore size, by optimizing the membrane capacitance and the external resistance that promises high-speed single-molecule sequencing by the ionic current at 10(6) base/s.