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Möbius Strip Downsized to Nanoscale Level

October 7, 2010

Scientists have used DNA origami to create a Möbius structure measuring only 50 nanometers.

The researchers, all from Arizona State University, were led by Hao Yan and Yan Liu, and included graduate students Dongran Han and Suchetan Pal.

"As nanoarchitects," Yan said, "we strive to create two classes of structure—geometric and topological."

To form the Möbius strip, the team relied on properties of DNA self-assembly, which had emerged in 2006 as a tool for nanostructure design thanks to the work of Paul Rothemund (California Institute of Technology). The method relies on a long, single stranded segment of DNA, used as a structural scaffold and guided through base pairing to assume a desired shape. Short, chemically synthesized "staple strands," composed of complementary bases, are used to hold the structure in place.

The team demonstrated the topological flexibility of a Möbius form using a folding and cutting—or DNA Kirigami—technique. It is composed of eleven double helices, assembled in parallel. Each double-helical length has a twist of 180 degrees along its central axis, before it reconnects with itself. The central helix circles around the length of the strip once. The other helices circle twice, while also twisting around the core helix by 180 degrees before reconnecting to close the Möbius loop.

Yan indicated that the team had relied on Dongran Han's superb sense of three-dimensional space. "Han and also Pal are particularly brilliant students," Yan said

Han indicated, "We want to push the Origami-Kirigami technology to create more sophisticated structures to demonstrate that we can make any arbitrary shape or topology using self-assembly."

The team summarized its findings in "Folding and Cutting DNA into Reconfigurable Topological Nanostructures," which appeared in Nature Nanotechnology (October 4, 2010).

Source: ASU Biodesign Institute (October 4, 2010)
Start Date: 
Thursday, October 7, 2010