A fresh look at DNA nanotechnology

Synthetic DNA structures for nanotechnological applications have experienced substantial success during the past decades benefiting from Seeman and his coworkers ’ pioneering work. In the last few years, some new branches have been emerging in this field. This review will summarize some recent progress in the authors ’ group. 1 Two-Dimensional DNA Triangle Arrays Designed with a Tensegrity Strategy Forming crystalline DNA lattices in one, two and even three dimensions has long been a hot topic of DNA nanotechnology. These artificially designed lattices are the basis for a variety of applications. The first success with a 2D DNA lattice was achieved in [22] with building blocks of double-crossover (DX) DNA molecules. Following that, rhombus motifs, triple-crossover molecules, and a cross motif were also constructed from branched four-arm Holliday junctions [19]. Here we present a tensegrity strategy for the construction of well-structured DNA triangle molecules [14]. A DNA triangle consists of three vertices (DNA four-arm junctions) and three sides (DNA duplexes). Although individual four-arm junctions are flexible, the rigidity of the three duplex edges restricts the freedom of the component four-arm junctions and only triangles can form. The shape of such a triangle is fully defined by the lengths of the three edges. By rational use of sticky-end cohesion, we have successfully assembled triangle arrays in one and two dimensions. Fig. 1 shows the design of some such triangle arrays and some atomic force microscope (AFM) images of such triangle arrays