Abstract

The paper folding mechanism has been widely adopted in building reconfigurable macroscale systems because of its unique capabilities and advantages in programming variable shapes and stiffness into a structure. However, it has been barely exploited in constructing molecular-level systems due to the lack of a suitable design principle, even though various dynamic structures based on DNA self-assembly have been developed. Here, we propose a method to harness the paper folding mechanism for making reconfigurable DNA origami structures. The main idea is to build a reference, planar wireframe structure whose edges follow a crease pattern in paper folding so that it can be folded into various target shapes. We could realize several paper-like folding and unfolding patterns using the DNA strand displacement with high yield. Orthogonal folding, repeatable folding and unfolding, folding-based microRNA detection, and fluorescence signal control were demonstrated. Stimuli-responsive folding and unfolding triggered by pH or light-source change were also possible. Moreover, by employing hierarchical assembly, we could expand the design space and complexity of the paper folding mechanism significantly in a highly programmable manner. Because of high programmability and scalability, we expect that the proposed paper-folding-based reconfiguration method would advance the development of complex molecular systems.