DNA Origami Rotaxanes: Tailored Synthesis and Controlled Structure Switching

Abstract

Mechanically interlocked supramolecular assemblies are appealing building blocks for creating functional nanodevices. Herein, we describe the multistep assembly of large DNA origami rotaxanes that are capable of programmable structural switching. We validated the topology and structural integrity of these rotaxanes by analyzing the intermediate and final products of various assembly routes by electrophoresis and electron microscopy. We further analyzed two structureâ switching behaviors of our rotaxanes, which are both mediated by DNA hybridization. In the first mechanism, the translational motion of the macrocycle can be triggered or halted at either terminus. In the second mechanism, the macrocycle can be elongated after completion of the rotaxane assembly, giving rise to a unique structure that is otherwise difficult to access.A new set of threads: Rotaxanes with a length of up to 200â nm were assembled by a DNA origami approach. The threaded macrocycles can be programmably docked at either dumbbell stopper, and the assemblies can be reconfigured to generate new, otherwise unfavorable rotaxane topologies.