Functionalizing designer DNA crystals with a triple-helical veneer

DNA is a very useful molecule for the programmed self-assembly of 2D and 3D nanoscale objects.¹ The design of these structures exploits Watson-Crick hybridization and strand exchange to stitch linear duplexes into finite assemblies.^2-4 The dimensions of these complexes can be increased by over five orders of magnitude through self-assembly of cohesive single-stranded segments (sticky ends).^5, 6 Methods that exploit the sequence addressability of DNA nanostructures will enable the programmable positioning of components in 2D and 3D space, offering applications such as the organization of nanoelectronics,⁷ the direction of biological cascades,⁸ and the structure determination of periodically positioned molecules by X-ray diffraction.⁹ To this end we present a macroscopic 3D crystal based on the 3-fold rotationally symmetric tensegrity triangle^3, 6 that can be functionalized by a triplex-forming oligonucleotide on each of its helical edges.