Stepwise DNA self-assemby of fixed-size nanostructures

Introduction: Self-assembled DNA nanostructures have been recognized over the last two decades as an interesting construction material in the field of nanotechnology1. Recently artificially designed self-assembled DNA nanostructures have been reported with various topological structures and functionalities: 1D and 2D periodically patterned structures2-5, 3D polyhedra6-7, nanomechanical devices8-10, and molecular computers11-13. Although DNA possesses requisite intrinsic characteristics -molecular scale recognition, self-organization, and structural properties, DNA-based nanostructures have only seen limited practical application in nanotechnology because of the lack of fixed-size controllability and full addressability. Here we report briefly on construction of size-controllable and fully addressable DNA-based nanomatrices (NM) consisting of two different crossed-junction tiles5 using a novel stepwise assembly technique. The stepwise assembly method makes use of a series of high-temperature and lowtemperature annealing steps which allows the reuse of identical DNA sequences at multiple locations within the NM without loss of full addressability. DNA nanostructures have been visualized by atomic force microscopy under buffer and their shapes and dimensions are shown to be in excellent agreement with designed structures.