SINGLE-MOLECULE DETECTION OF ARTIFICIAL AUTONOMOUS NANOWALKER USING MAGNETIC TWEEZERS

Abstract

Single-molecule mechanical characterization for artificial DNA nanowalkers, while crucial in the development of this field, is a challenge to date. In this thesis, a procedure employing magnetic tweezers to detect an autonomous non-burn-bridge DNA nanowalker, is developed. To the writer’s knowledge, it is the first time that a single artificial nanowalker is detected in its directional motion against a mechanical force. In this setup, an in-situ assembly of the walker-track system was achieved in a stepwise fashion. This is a force-assisted multi-step annealing process by stretching a single-stranded DNA template via a single paramagnetic bead, after which the same bead is switched to the walker for motility detection. Therefore, single-molecule level quantities were obtained by analyzing the stepping signals. This study establishes a single-molecule platform to characterize the mechanical output of artificial nanowalkers, and the findings add fresh insights into chemomechanical conversion at the single-molecule level.