Propulsion of Magnetic Beads Asymmetrically Covered with DNA Origami Appendages

Abstract

Eukaryotic cells that swim by the beating of nanoscale elastic filaments (flagella) present a promising locomotion paradigm for man‐made analogues essential for next‐generation in‐vivo treatments and for the study of collective phenomena at the low Reynolds number limit. However, artificial analogues have been limited to many microns in size due to the engineering challenges of fabricating actable flexible filaments at the nanoscale—thereby narrowing the application scope. Here, made‐to‐order nanoscale filaments designed on the molecular level are fabricated using the DNA‐origami technique. It is found that magnetic beads anisotropically covered with such bundles move in a ballistic fashion when wagged back and forth under an external magnetic field. Furthermore, by comparing bead dynamics at a range of bundle coverages and driving frequencies, compelling evidence is amassed to suggest that this ballistic motion is imparted by the beating of the DNA origami filaments as synthetic flagella. This proof‐of‐concept work opens up avenues for further made‐for‐purpose appendages designed using DNA self‐assembly and with it ever more complex locomotion on the nano and microscale.