Random Walking Dynamics of a DNA Nanorobot on a Two-Dimensional Nanopore Track

Recent proof-of-concept studies have suggested that multinanopore surfaces can serve as solid-state tracks for manipulating the directional walking of DNA nanorobots. However, certain specialized tasks of the nanorobots, such as searching for and sorting cargo, depend on their nondirectional (random) walking capability. In this study, the random walking performance of a DNA-legged nanorobot on a two-dimensional nanopore track is investigated using Langevin dynamics simulations and theoretical calculations. The results show that diffusive mobility of the nanorobot initially increases and then decreases with the electric potential inside the nanopores, which can be tuned via external voltage perpendicular to the track and surface charge density of the nanopores. Additionally, the nanorobot exhibits Lévy-type motion, whose mean squared displacement scaling with elapsed time agrees with previous experimental results on biological tracks, suggesting that the walking mechanisms elucidated here may extend to the nanorobots in different environments.