Modular access to structurally switchable 3D discrete DNA assemblies

In this contribution we describe a facile method to access a large number of three-dimensional discrete DNA assemblies. The approach involves the use of single-stranded and cyclic 2D DNA building blocks, of predefined geometry, as the faces or sides of the objects to be constructed. Any target three-dimensional discrete object that could be retrosynthetically broken down into a combination of the discrete 2D shapes, could in principle be easily accessed using this method. Using triangle 3, square 4, pentagon 5, and hexamer 6, we constructed triangular, cubic, pentameric, and hexameric prisms, as well as the more complex heteroprism HP and biprism BP assemblies in quantitative yields. The use of single-stranded DNA building blocks inherently allows for dynamic character and addressability. Using a series of rigidifying and eraser strands, we generated a triangular prism capable of structural oscillation between three predefined lengths. The easy access to a large number of complex three-dimensional discrete DNA objects that are also dynamic, in response to external stimuli, promises to expand the applications of 3D DNA construction in many areas of nanoscience, drug delivery, and biological chemistry.