Bilayer-spanning DNA nanopores with voltage-switching between open and closed state

Area of Science:

• Nanotechnology
• Biomaterials Science
• Molecular Biophysics

Background:

• DNA nanopores are artificial nanostructures mimicking biological pores.
• They hold promise for applications in biosensing, drug delivery, and nanofluidics.
• Understanding their fundamental properties is key for advancing nanobiotechnology.

Purpose of the Study:

• To generate and characterize a DNA nanopore based on a six-helix-bundle architecture.
• To investigate the voltage-dependent conductance states of the DNA nanopore.
• To clarify the ion-conducting pathway and pore dimensions.

Main Methods:

• Single-channel current recordings were used to characterize the DNA nanopore.
• Conductance measurements were performed as a function of transmembrane voltage.
• Poly(ethylene glycol) (PEG) size was varied to probe the pore's inner width.

Main Results:

• The DNA nanopore exhibits two distinct voltage-dependent conductance states: high at low voltage and low at high voltage.
• Conductance changes with PEG size confirmed the pore's inner width and ion-conducting path through the lumen.
• Voltage-induced conformational or orientational changes likely cause the low-conductance state.

Conclusions:

• The study elucidates the voltage-dependent behavior of DNA nanopores, settling previous discrepancies.
• Findings confirm the unobstructed lumen as the primary ion pathway.
• This work supports the advancement of DNA nanopores for nanobiotechnology applications.