Homopolymer and heteropolymer translocation through patterned pores under fluctuating forces

Area of Science:

• Polymer physics
• Soft matter physics
• Computational biophysics

Background:

• Understanding polymer translocation through nanopores is crucial for DNA sequencing and drug delivery.
• Semiflexible polymers exhibit complex behaviors influenced by chain stiffness and external forces.
• Patterned pores offer tunable environments for controlling translocation dynamics.

Purpose of the Study:

• To investigate the translocation dynamics of semiflexible polymers through patterned pores under a time-dependent driving force.
• To determine the impact of polymer stiffness, pore properties, and force characteristics on translocation efficiency.
• To develop a sequencing approach for heteropolymers based on translocation behavior.

Main Methods:

• Langevin dynamics simulations were employed to model polymer translocation.
• Time-dependent (oscillating and constant) driving forces were applied.
• System parameters included polymer stiffness, pore geometry, and pore-polymer interactions.
• Translocation times and distributions were analyzed.

Main Results:

• Oscillating forces significantly enhance translocation speed compared to constant forces of equivalent average magnitude.
• Enhanced translocation is correlated with polymer stiffness and pore stickiness.
• Pore arrangement critically influences translocation dynamics, modulated by polymer stiffness and pore-polymer interactions.
• Heterogeneous polymers show varied translocation times based on segment properties under oscillating forces.

Conclusions:

• Time-dependent forces, particularly oscillating ones, offer a mechanism to accelerate polymer translocation through patterned nanopores.
• Polymer stiffness and pore characteristics are key factors in optimizing translocation.
• The study proposes a novel sequencing method for heteropolymers by exploiting differential translocation behaviors influenced by pore properties.