Placement and orientation of individual DNA shapes on lithographically patterned surfaces

Artificial DNA nanostructures show promise for the organization of functional materials to create nanoelectronic or nano-optical devices. DNA origami, in which a long single strand of DNA is folded into a shape using shorter 'staple strands', can display 6-nm-resolution patterns of binding sites, in principle allowing complex arrangements of carbon nanotubes, silicon nanowires, or quantum dots. However, DNA origami are synthesized in solution and uncontrolled deposition results in random arrangements; this makes it difficult to measure the properties of attached nanodevices or to integrate them with conventionally fabricated microcircuitry. Here we describe the use of electron-beam lithography and dry oxidative etching to create DNA origami-shaped binding sites on technologically useful materials, such as SiO_2 and diamond-like carbon. In buffer with ~ 100 mM MgCl_2, DNA origami bind with high selectivity and good orientation: 70–95% of sites have individual origami aligned with an angular dispersion (±1 s.d.) as low as ±10° (on diamond-like carbon) or ±20° (on SiO_2)

The Biomolecular Computation Paradigm: A Survey in Massive Biological Computation

Part 3: MHDWInternational audienceBiomolecular computation is the scientific field focusing on the theory and practice of encoding combinatorial problems in ordinary DNA strands and applying standard biology lab operations such as cleansing and complementary sequence generation to them in order to compute an exact solution. The primary advantage offered by this computational paradigm is massive parallelism as the solution space is simultaneously searched. On the other hand, factors that need to addressed under this model are the DNA volume growth and computational errors attributed to inexact DNA matching. Biomolecular computation additionally paves the way for two- and three-dimensional self assemblying biological tiles which are closely linked at a theoretical level to a Turing machine, establishing thus its computational power. Applications include medium sized instances of TSP and the evaluation of the output of bounded fan-out Boolean circuits