Ionic Liquid Decelerates Single-Stranded DNA Transport through Molybdenum Disulfide Nanopores

Area of Science:

• Materials Science
• Biophysics
• Computational Chemistry

Background:

• Two-dimensional (2D) materials with nanopores offer high spatial resolution for DNA sequencing.
• Fast DNA translocation through nanopores limits sequencing fidelity.
• Ionic liquids have shown potential to slow DNA translocation in MoS2 nanopores, but the mechanism is unclear.

Purpose of the Study:

• To computationally investigate and experimentally identify the mechanism of ssDNA translocation retardation by BmimCl ionic liquid in a MoS2 nanopore.
• To understand the molecular interactions governing DNA movement for improved nanopore sequencing control.

Main Methods:

• All-atom molecular dynamics simulations.
• Experimental validation of computational findings.
• Analysis of ion-DNA and ion-nanopore interactions.

Main Results:

• Bmim+ ions strongly interact with ssDNA, generating a dragging force that decelerates translocation.
• Bmim+ ions preferentially bind to the sulfur edges of the MoS2 nanopore.
• Bmim+ ions within the pore act as steric blockers and form π-π stackings with nucleobases, further restricting ssDNA motion.

Conclusions:

• Molecular dynamics simulations elucidate the crucial role of BmimCl ionic liquid in controlling ssDNA translocation through MoS2 nanopores.
• Understanding these molecular interactions can guide the rational design of ionic liquids for enhanced nanopore DNA sequencing.