Construction of a Polyhedral DNA 12-Arm Junction for Self-Assembly of Wireframe DNA Lattices.

A variety of different tiles for the construction of DNA lattices have been developed since the structural DNA nanotechnology field was born. The majority of these are designed for the realization of close-packed structures, where DNA helices are arranged in parallel and tiles are connected through sticky ends. Assembly of such structures requires the use of cation-rich buffers to minimize repulsion between parallel helices, which poses limits to the application of DNA nanostructures. Wireframe structures, on the other hand, are less susceptible to salt concentration, but the assembly of wireframe lattices is limited by the availability of tiles and motifs. Herein, we report the construction of a polyhedral 12-arm junction for the self-assembly of wireframe DNA lattices. Our approach differs from traditional assembly of DNA tiles through hybridization of sticky ends. Instead, the assembly approach presented here uses small polyhedral shapes as connecting points and branch points of wires in a lattice structure. Using this design principle and characterization techniques, such as transmission electron microscopy, single-particle reconstruction, patterning of gold nanoparticles, dynamic light scattering, UV melting analyses, and small-angle X-ray scattering among others, we demonstrated formation of finite 12-way junction structures, as well as 1D and 2D short assemblies, demonstrating an alternative way of designing polyhedral structures and lattices.