On the distribution of DNA translocation times in solid-state nanopores: an analysis using Schrödinger's first-passage-time theory.
On the distribution of DNA translocation times in solid-state nanopores: an analysis using Schrödinger's first-passage-time theory.
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DOI：
10.1088/0953-8984/25/37/375102
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发表时间：
2013-09-18
期刊：
影响因子：
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通讯作者：
Ling XS
中科院分区：
文献类型：
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作者：
Ling DY;Ling XS
在这篇简短的笔记中，对最近提出的线性DNA易位的一维有偏扩散模型的解进行了修正，并对文[1]中的数据进行了新的分析。我们最近指出，这个一维线性移位模型与薛定谔在Enrenhaft-Millikan电荷测量中所考虑的模型是等价的。在这里，我们将薛定谔的首次通过时间分布公式应用于中的数据集。研究发现，薛定谔公式可以用来描述DNA在固体纳米孔中移位的时间分布。这些拟合产生了两个有用的参数：DNA移位的漂移速度和DNA在纳米孔内的扩散常数。结果表明，DNA的转位有两种模式：(I)在低电压下，与Smoluchowski的线性电泳法有明显的偏离，我们将其归因于势垒效应；(Ii)在高电压下，转位速度是外加电场的线性函数。在区域II中，表观扩散常数与外加电场呈二次曲线关系，这可能是由于纳米孔道中的电渗场引起了泰勒弥散效应。这一分析得到纳米孔内DNA片段的无色散扩散常数值为11.2nm2/µS，这与斯托克斯-爱因斯坦理论在定量上是一致的。讨论了薛定谔公式在DNA测序中的应用。
In this short note, a correction is made to the recently proposed solution to a 1D biased diffusion model for linear DNA translocation and a new analysis will be given to the data in. It was pointed out by us recently that this 1D linear translocation model is equivalent to the one that was considered by Schrödinger for the Enrenhaft-Millikan measurements on electron charge. Here we apply Schrödinger’s first-passage-time distribution formula to the data set in. It is found that Schrödinger’s formula can be used to describe the time distribution of DNA translocation in solid-state nanopores. These fittings yield two useful parameters: drift velocity of DNA translocation and diffusion constant of DNA inside the nanopore. The results suggest two regimes of DNA translocation: (I) at low voltages, there are clear deviations from Smoluchowski’s linear law of electrophoresis which we attribute to the entropic barrier effects; (II) at high voltages, the translocation velocity is a linear function of the applied electric field. In regime II, the apparent diffusion constant exhibits a quadratic dependence on applied electric field, suggesting a mechanism of Taylor dispersion effect likely due the electro-osmotic flow field in the nanopore channel. This analysis yields a dispersion-free diffusion constant value of 11.2 nm2/µs for the segment of DNA inside the nanopore which is in agreement with Stokes-Einstein theory quantitatively. The implication of Schrödinger’s formula for DNA sequencing is discussed.