Current blockade in nanopores in the presence of double-stranded DNA and the microscopic mechanisms.
Current blockade in nanopores in the presence of double-stranded DNA and the microscopic mechanisms.
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DOI：
10.1021/jp909564d
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发表时间：
2010-02-11
期刊：
影响因子：
--
通讯作者：
Cui S
中科院分区：
文献类型：
--
作者：
Cui S
我们已经进行了布朗动力学计算来研究纳米孔中dsDNA的电流阻断机制。我们发现随着离子浓度的降低，阻断电流由负向正交叉，与实验结果相似。除了体积排斥和对流凝聚外，我们发现双电层重叠是电流阻塞的一个重要因素。双电层重叠导致在dsDNA封闭的纳米孔中dsDNA和壁的紧邻区域之外的离子浓度低于在开放的纳米孔中远离壁的平台离子浓度，因此对封闭电流有重要贡献。基于计算的纳米孔中的离子分布函数，我们研究了对dsDNA的反离子缩合。我们发现，过量的反式缩合是约60%的双链DNA上的电荷，这是从实验中获得的范围内。我们进行了平衡和非平衡（在外加电场下）布朗动力学模拟，以计算纳米孔中离子的平均迁移率。发现计算的离子迁移率在DNA封闭的纳米孔中降低。
We have carried out Brownian Dynamics calculations to investigate the mechanism of current blockade by dsDNA in a nanopore. We find that the blockade current crosses over from negative to positive as the ionic concentration decreases, similar to experiment. In addition to the volume exclusion and the counterion condensation, we find that the electric double layer overlap is a significant factor in the current blockade. The electric double layer overlap causes the ionic concentration beyond the immediate neighborhood of dsDNA and the wall to be lower in dsDNA-blocked nanopore than the plateau ionic concentration away from the wall in an open nanopore, thus contribute importantly to the blockade current. Based on the calculated ion distribution function in the nanopore, we examined the counterion condensation to the dsDNA. We find the excess counterion condensation to be about 60% of the charge on the dsDNA, which is within the range of those obtained from experiments. We performed equilibrium and non-equilibrium (under an applied electric field) Brownian dynamics simulations to calculate the average mobility of the ions in nanopore. The calculated ion mobility is found to be reduced in DNA-blocked nanopore.
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影响因子：
4.4
作者：
MONTORO, JCG;ABASCAL, JLF
通讯作者：
ABASCAL, JLF
影响因子：
19.6
作者：
Keyser, Ulrich F.;Koeleman, Bernard N.;Dekker, Cees
通讯作者：
Dekker, Cees
影响因子：
10.8
作者：
Chang, H;Kosari, F;Bashir, R
通讯作者：
Bashir, R
影响因子：
--
作者：
Lee, SH;Rasaiah, JC
通讯作者：
Rasaiah, JC
DOI：
10.1073/pnas.93.24.13770
发表时间：
1996-11-26
影响因子：
11.1
作者：
Kasianowicz, JJ;Brandin, E;Deamer, DW
通讯作者：
Deamer, DW