Double-stranded DNA diffusion in slitlike nanochannels
Double-stranded DNA diffusion in slitlike nanochannels
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DOI：
10.1021/ma061047t
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发表时间：
2006-09-05
期刊：
影响因子：
5.5
通讯作者：
Doyle, Patrick S.
中科院分区：
文献类型：
--
作者：
Balducci, Anthony;Mao, Pan;Doyle, Patrick S.
我们提出了双链 DNA 在狭缝状通道中扩散的实验研究。通道高度跨越从中度限制（与 DNA 的整体旋转半径相似的高度）到强限制（与持久长度相似的高度）的范围。扩散率随通道高度的变化与斑点模型预测不同。当通道高度小于整体回转半径时，扩散率与分子量成反比。这种缩放表明了流体动力学筛选。缩放分析表明，流体动力学相互作用的筛选是由两种机制的组合产生的。使用 Zimm 预平均近似后，细缝扰动速度的独特对称性和聚合物构象的各向同性性质共同导致由于对称性而导致的流体动力学相互作用的抵消。我们还发现，远场速度大小的代数衰减足以消除准二维聚合物在良溶剂中扩散时的大尺度流体动力学协同性。
We present an experimental study of double-stranded DNA diffusion in slitlike channels. The channel heights span the regime from moderate confinement (height similar to bulk radius of gyration of the DNA) to strong confinement (height similar to persistence length). Scalings of diffusivity with channel height differ from blob model predictions. The diffusivity scales inversely with molecular weight when the channel height is smaller than the bulk radius of gyration. This scaling is indicative of hydrodynamic screening. A scaling analysis shows that the screening of hydrodynamic interactions arises from a combination of two mechanisms. After using a Zimm preaverage approximation, the unique symmetry of the thin-slit disturbance velocity and the isotropic nature of the polymer conformation together cause a cancellation of hydrodynamic interactions due to symmetry. We also find that the algebraic decay of the far-field velocity magnitude is sufficient to eliminate large-length scale hydrodynamic cooperativity in diffusion of quasi-two-dimensional polymers in good solvents.