Star-shaped polymer translocation into a nanochannel: Langevin dynamics simulations

Abstract

The dynamics of a star-shaped polymer translocation pulled by a single arm through a nanochannel is investigated using three-dimensional Langevin dynamics simulations. The pulling force is applied on the terminal monomer of the leading arm in order to mimic the motion of chains subject to a combination of magnetic and optical tweezers in real experimental setups. The effect of channel dimensions and magnitude of the pulling force as well as the chain size and functionality on the chain’s translocation dynamics is extensively examined. The variation of the mean translocation time 〈τ〉 with respect to channel length and diameter exhibits a non-trivial behavior characterized by an abrupt change in the translocation dynamics for chains with higher functionalities f. The dependence of 〈τ〉 upon channel aspect ratio yields also a regime change for the transport dynamics for chains with larger functionalities. Moreover, the average exit time with respect to chains total mass N and to the magnitude of the pulling force F are found to follow scaling laws in agreement with theoretical predictions.