Wang Junfang, Wang Yilin, Luo Kaifu
CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, and Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
J Chem Phys. 2015 Feb 28;142(8):084901. doi: 10.1063/1.4913468.
Polymer translocation through nanopore has potential technological applications for DNA sequencing, where one challenge problem is to slow down translocation speed. Inspired by experimental findings that kinked nanopores exhibit a large reduction in translocation velocity compared with their straight counterparts, we investigate the dynamics of polymer translocation through kinked nanopores in two dimensions under an applied external field. With increasing the tortuosity of an array of nanopores, our analytical results show that the translocation probability decreases. Langevin dynamics simulation results support this prediction and further indicate that with increasing the tortuosity, translocation time shows a slow increase followed by a rapid increase after a critical tortuosity. This behavior demonstrates that kinked nanopores can effectively reduce translocation speed. These results are interpreted by the roles of the tortuosity for decreasing the effective nanopore diameter, increasing effective nanopore length, and greatly increasing the DNA-pore friction.
聚合物通过纳米孔的转位在DNA测序方面具有潜在的技术应用，其中一个具有挑战性的问题是减缓转位速度。受实验结果启发，即与直纳米孔相比，扭结纳米孔的转位速度大幅降低，我们研究了在外部施加场作用下聚合物在二维扭结纳米孔中的转位动力学。随着纳米孔阵列曲折度的增加，我们的分析结果表明转位概率降低。朗之万动力学模拟结果支持这一预测，并进一步表明随着曲折度增加，转位时间先缓慢增加，在达到临界曲折度后迅速增加。这种行为表明扭结纳米孔可以有效降低转位速度。这些结果可通过曲折度在减小有效纳米孔直径、增加有效纳米孔长度以及大幅增加DNA与孔之间摩擦力方面所起的作用来解释。
