Stiff filamentous virus translocations through solid-state nanopores

Area of Science:

• Biophysics
• Nanotechnology
• Polymer Physics

Background:

• Nanopores detect single molecules via ionic conductance changes as biopolymers translocate.
• Understanding polymer translocation through nanopores is crucial for applications like DNA sequencing.

Purpose of the Study:

• To investigate the voltage-driven dynamics and translocation physics of the stiff filamentous virus fd through nanopores.
• To explore the role of electric fields, stiffness, and Brownian motion in virus translocation.

Main Methods:

• Experimental studies of virus fd translocation through nanopores.
• Simulations to model the voltage-driven dynamics and interactions.

Main Results:

• Electric fields promote fd capture by aligning it with the nanopore but can cause sideways motion after failed attempts.
• The stiff fd virus translocates linearly, showing voltage-independent mobility and adhering to first-passage-time statistics.
• Brownian motion partially explains translocation velocity fluctuations, with an additional, partially understood voltage-dependent contribution observed.

Conclusions:

• The translocation of stiff polymers like virus fd through nanopores is governed by a complex interplay of electric fields, membrane interactions, and thermal fluctuations.
• While linear translocation is favored due to stiffness, the dynamics reveal unexpected contributions to velocity fluctuations beyond simple Brownian motion.