Threading immobilized DNA molecules through a solid-state nanopore at >100 μs per base rate

Area of Science:

• Nanotechnology
• Biophysics
• Genomics

Background:

• Solid-state nanopore technology offers a promising platform for DNA sequencing.
• Achieving precise control over DNA translocation speed is crucial for high-resolution sequencing.
• Previous methods lacked the necessary temporal resolution for individual base detection.

Purpose of the Study:

• To design and construct an apparatus for controlled DNA translocation through solid-state nanopores.
• To enable DNA sequencing at a single-base resolution.
• To simultaneously measure ionic current, tip position, and tip vibrational amplitude.

Main Methods:

• A DNA-tethered probe tip was positioned near a solid-state nanopore using a tuning fork-based feedback force sensor and nanopositioning system.
• The apparatus controlled DNA molecule movement speed during capture and release from the nanopore.
• Simultaneous measurements of ionic current, tip position, and tip vibrational amplitude were performed.

Main Results:

• A DNA strand translocation rate of >100 μs/base (<1 nm/ms) was achieved in silicon nitride nanopores.
• This translocation speed is significantly slower than previously reported methods, allowing for single-base resolution.
• The apparatus successfully measured DNA capture/release distances and current blockage signals for λ DNA.

Conclusions:

• The developed apparatus enables ultra-slow DNA translocation, facilitating single-base resolution in solid-state nanopore sequencing.
• This technology provides a new tool for high-resolution DNA analysis and sequencing.
• The ability to measure multiple signals simultaneously enhances the understanding of DNA-nanopore interactions.