Electrically Facilitated Translocations of Proteins through Silicon Nitride Nanopores: Conjoint and Competitive Action of Diffusion, Electrophoresis, and Electroosmosis
Electrically Facilitated Translocations of Proteins through Silicon Nitride Nanopores: Conjoint and Competitive Action of Diffusion, Electrophoresis, and Electroosmosis
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DOI：
10.1021/nl100861c
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发表时间：
2010-06-01
期刊：
影响因子：
10.8
通讯作者：
Rant, Ulrich
中科院分区：
文献类型：
--
作者：
Firnkes, Matthias;Pedone, Daniel;Rant, Ulrich
固态纳米孔具有用于探测单个蛋白质的巨大潜力;然而，发现蛋白质通过纳米孔是复杂的，并且观察到关于通过方向、速率和持续时间的意外易位行为。在这里，我们研究的模型蛋白质（抗生物素蛋白）通过氮化硅纳米孔的移位，专注于电动效应，促进蛋白质运输通过孔。的纳米孔zeta电位zeta（孔）孔和蛋白质zeta电位zeta（蛋白质）蛋白质独立测量作为溶液pH值的函数。我们的研究结果表明，电渗运输可以增强或主导和逆转电泳运输纳米孔。易位行为是合理的，分别占蛋白质和孔的电荷状态，产生的易位方向可以预测根据不同的ζ电位，ζ（蛋白质）-ζ（孔）。当电泳和电渗相互抵消时，扩散成为一种有效的（和偏压无关的）机制，其促进蛋白质以显著的速率穿过孔运输。
Solid-state nanopores bear great potential to be used to probe single proteins; however, the passage of proteins through nanopores was found to be complex, and unexpected translocation behavior with respect to the passage direction, rate, and duration was observed. Here we study the translocation of a model protein (avidin) through silicon nitride nanopores focusing on the electrokinetic effects that facilitate protein transport across the pore. The nanopore zeta potential zeta(pore) pore and the protein zeta potential zeta(protein) protein are measured independently as a function of solution pH. Our results reveal that electroosmotic transport may enhance or dominate and reverse electrophoretic transport in nanopores. The translocation behavior is rationalized by accounting for the charging states of the protein and the pore, respectively; the resulting translocation direction can be predicted according to the difference in zeta potentials, zeta(protein) - zeta(pore). When electrophoresis and electroosmosis cancel each other out, diffusion becomes an effective (and bias-independent) mechanism which facilitates protein transport across the pore at a significant rate.