A DNA bipedal nanowalker with a piston-like expulsion stroke.

Area of Science:

• Nanotechnology
• Molecular Engineering
• Biophysics

Background:

• Developing artificial molecular walkers beyond traditional designs is crucial for advancing nanotechnology.
• Systematic development of non-burn-bridge nanowalkers has been challenging.

Purpose of the Study:

• To report a rationally designed DNA walker-track system for non-burn-bridge nanowalkers.
• To experimentally verify a general expulsion regime for nanowalker implementation.

Main Methods:

• Designed a DNA walker with an optically powered engine utilizing quadruplex-duplex conformational changes.
• Utilized an energy-absorbing extension and piston-like expulsion stroke for directional movement.
• Fabricated three walkers of varying sizes and conducted fluorescence motility experiments.

Main Results:

• Experimentally verified the proposed general expulsion regime for nanowalkers.
• Demonstrated directional movement driven by an unzipping-shearing asymmetry in the expulsion stroke.
• Observed a distinctive size dependence in walker performance, unlike previously reported walkers.

Conclusions:

• The study successfully implemented a novel non-burn-bridge nanowalker based on an expulsion mechanism.
• Identified unique technical requirements for expulsive nanowalkers.
• The DNA design is adaptable for creating similar molecular walkers from diverse molecules.