Unforced translocation of a polymer chain through a nanopore: The solvent effect

Abstract

The authors have performed the Langevin dynamics simulation to investigate the unforced polymer translocation through a narrow nanopore in an impermeable membrane. The effects of solvent quality controlled by the attraction strength lambda of the Lennard-Jones cosine potential between polymer beads and beads on two sides of the membrane on the translocation processes are extensively examined. For polymer translocation under the same solvent quality on both sides of the membrane, the two-dimensional and three-dimensional simulations confirm the scaling law of tautrans approximately N1+2upsilon for the translocation in the good solvent, where tautrans is the translocation time, N is the chain length, and upsilon is the Flory exponent. For the three-dimensional polymer translocation under different solvent qualities on two sides of the membrane, the translocation efficiency may be notably improved. The scaling law between tautrans and N varies from tautrans approximately N1+2upsilon to tautrans approximately N with the increase of the difference of solvent qualities, and the crossover occurs at the theta temperature point, where a scaling law of tautrans approximately N1.27 is found. The simulation results here also show that the translocation time changes from a wide and asymmetric distribution with a long tail to a narrow and symmetric distribution with the increase of the difference of the solvent qualities.

Polymer translocation out of planar confinements

“…The data collapse is a further test that rules out the τ d scaling as N 1+2ν 2D , as reported in Ref. [15,17,18]: in fact the left panel of Fig. 7 suggests that P (τ d ), the probability distribution for the dwell [17].…”

“…(i) Unbiased translocation: authors two-dimensions three-dimensions Chuang et al [15] 2.5 − Luo et al [17] 2.50 ± 0.01 − Wei et al [18] 2 (ii) Field-driven translocation:…”

Nondriven polymer translocation through a nanopore: Computational evidence that the escape and relaxation processes are coupled

“…Moreover, recent advances in manipulating and analyzing DNA moving through natural [1,2] or synthetic nanopores [3] strongly suggest that such mechanical systems could eventually lead to the development of new ultrafast sequencing techniques [1,4,5,6,7,8,9,10,11]. However, even though a great number of theoretical [12,13,14,15,16,17,18,19,20,21,22,23] and computational [24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42] studies have been published on the subject, there are still many unanswered questions concerning the fundamental physics behind such a process.…”

Translocation of stiff polymers through a nanopore driven by binding particles

“…Another mechanism utilizes a chemical potential gradient across the membrane. Examples include translocation of chains under different solvent conditions [18][19][20], and that under the chemical * Author to whom the correspondence should be addressed; Electronic address: kluo@ustc.edu.cn potential gradient due to the binding particles (BPs) on the two sides of the membrane [9,. In what follows, we concentrate on polymer translocation in the presence of BPs.…”