Structural DNA nanotechnology: from design to applications

Abstract

The exploitation of DNA for the production of nanoscale architectures presents a young yet paradigm breaking approach, which addresses many of the barriers to the self-assembly of small molecules into highly-ordered nanostructures via construct addressability. There are two major methods to construct DNA nanostructures, and in the current review we will discuss the principles and some examples of applications of both the tile-based and DNA origami methods. The tile-based approach is an older method that provides a good tool to construct small and simple structures, usually with multiply repeated domains. In contrast, the origami method, at this time, would appear to be more appropriate for the construction of bigger, more sophisticated and exactly defined structures.

Keywords: DNA nanotechnology; DNA origami; nanostructures; self-assembly.

Figure 1

Basic DNA structures for tile-based self-assembly. (a) Four-arm junction with sticky ends; and (b) Its detailed molecular model; (c) Double crossover motif (DX); (d) Triple crossover motifs (TX).

Figure 2

Schematic illustration of DNA folding in origami construction. A long ssDNA (usually circular) is treated with an excess number of shorter complementary strands, so called “staple strands”. Sample annealing chart in the DNA origami construction is shown in the lower-left. The annealing process starts with heating of the solution, followed by fast cooling to 80 °C with further cooling to 60 °C in a slower process. The sample is cooled down very slowly to 20 °C.

Figure 3

3D DNA box origami. (a) Six flat square-shaped origami domains which by their connection (black lines in (b)) will form a 3D DNA box origami; (c–e) DNA box origami in different states.

Figure 4

3D solid DNA origami structures; (a) flat design of the crossover pattern for the designed structure. Blue line represents the scaffold and the black lines represent the staple strands; (b) Schematic model of the multilayer 3D origami design where three layers of DNA helices are connected via many crossovers. The crossover patterns for each segment are illustrated in (a).