Soft Materials Seminar - "Synthesis and Characterization of Polycatenated DNA Crystals"

Mechanically interlocked structures exhibit behaviors distinct from those of continuous materials because their properties emerge from geometry and topology in addition to chemical composition. Polycatenated architectures, such as chainmail, are especially attractive because they provide flexibility, rigidity, and reconfigurability. Although topological constraints have been studied at the macroscale and in molecular machines, the precise realization of interlocked 3D lattice structures at the nanoscale remains a major synthetic challenge.

    Here, we present the bottom-up self-assembly of nanoscale polycatenated architected materials (nano-PAMs) using DNA origami. By combining the structural programmability of DNA origami with nanoparticle-templated assembly, we synthesize and characterize highly ordered polycatenated lattices with designed spatial symmetries. Specifically, we demonstrate the assembly of 3D crystalline superlattices through the site-selective interlocking of DNA origami-based topological motifs. We further establish the versatility of this synthetic strategy by systematically designing the geometries of the DNA origami building blocks and templating nanoparticles to access a diverse set of nano-PAM structures.

    Furthermore, using nano-PAM as a model system, we seek to investigate the unusual thermal behavior inherent to mechanically interlocked colloidal crystals by probing temperature-dependent changes in order mainly driven by thermal fluctuations. By rationally programming the degree of structural order at the nanoscale, these architectures could enable spatial templating of various materials to modulate their resultant photonic, mechanical, phononic, and acoustic behaviors. More broadly, this design paradigm establishes a versatile platform for constructing nano-PAMs with tunable properties, opening opportunities for stimuli-responsive and reconfigurable nanoscale systems.