Two-Dimensional DNA-Origami Arrays The work is by Wenyan Liu, Dr. Hong Zhong, Dr. Risheng Wang, and Prof. Nadrian C. Seeman.
DNA origami gets large: A double-layer DNA-origami tile with two orthogonal domains underwent self-assembly into well-ordered 2D DNA arrays with edge dimensions of 2–3 μm (see schematic representation and AFM image). This size is likely to be large enough to connect bottom-up methods of patterning with top-down approaches.
They used this origami method to fold the DNA into the shapes they needed: cross-shaped tiles. The crosses consist of two mutually orthogonal overlapping strips, like two plasters stuck on top of each other to make a cross. On the four sides of the cross there are several sticky ends; the sticky ends opposite each other are identical. The researchers used two different sets of origami crosses with different sticky ends. These ends are designed so that the crosses bind together in an alternating pattern through a self-organization process—such that the lower strip of one cross is always bound to the upper strip of its neighbor. This results in a two-dimensional structure that has a lattice-like woven appearance when viewed through an electron microscope. The alternating construction of upward and downward curved crosses is necessary to produce a planar surface. Randomly assembled crosses often lead to tubular structures.
“Our new approach could smooth the way for the industrial production of nanostructures through molecular self-organization processes,” hopes Seeman.