Self-Assembling DNA Makes Super 3-D Nano Machines [View All]

William Shih has a bridge to sell, but you’ll need a powerful microscope to see it: It’s built entirely from DNA strands, handrails and all.

The bridge is just one of a whole range of intricate three-dimensional shapes Shih has crafted using DNA’s unique capacity for precise self-assembly. In a study Thursday in Science, his team has shown they can even control the precise curvature of these tiny structures, which is key to making wheels, hooks and gears.

Unlike building nano portraits of Obama, This isn’t just an artistic exercise. Scientists in the burgeoning field of structural DNA nanotechnology are exploring DNA’s potential as raw material for next-generation circuits, sensors and biomedical devices. Advocates say it could become the new go-to material for engineers, scientists and clinicians.

“DNA is the world’s greatest architectural material, in my opinion,” said NYU chemist Ned Seeman, the field’s founder and lonely apostle.

In addition to its well-known sequence specificity — A only binds T, G only binds C — DNA’s structural properties have been intensely studied for over half a century, and one can predict the atomic-level structure of virtually any DNA construct with remarkable accuracy. Since the 1980s, Seeman has been quietly designing DNA strands that self-assemble into interlocking tiles, three-dimensional polyhedrons and even nanomachines that automatically ‘walk’ along other DNA strands.

In 2006, the technology finally entered the scientific limelight, heralded by a Nature cover festooned with cheerful smiley faces, each composed of a long, folded strand of DNA meticulously wrangled into shape with tiny DNA “staples,” a technique that its inventor, CalTech computer scientist Paul Rothemund, termed “DNA origami.”

http://www.wired.com/wiredscience/2009/08/nanodna/