Goethe University professor Alexander Heckel and his doctoral student Thorsten Schmidt made the artificial structures from two interlocking loops of DNA—known as “catenane,” from the Latin word for “chains”—in a single drop of water. Measuring a mere 18 nanometers in size (1 nanometers equals 10 one-billionths of a meter), the rings are likely the tiniest pledges of fidelity in existence. But although Schmidt got married while he was working on the experiment, the nanoforms aren’t just romantic novelties—they’re also freely pivotable, which means they could be useful in molecular machines or motors.


DNA nanotechnology, the new discipline responsible for the structures, combines concepts from biology, chemistry, material science, and physics. And while they may appear trite, the rings are an important milestone in DNA nanoarchitecture.

While they may appear trite, the rings are an important milestone in DNA nano-architecture.

“We still have a long way to go before DNA structures such as the catenan can be used in everyday items,” says Heckel. “But structures of DNA can, in the near future, be used to arrange and study proteins or other molecules that are too small for a direct manipulation, by means of auto-organization.”

Schmidt dedicated their report, which was published in the March 2011 issue of Nano Letters, to his wife, Diana Gonçalves Schmidt. Don’t worry, she totally gets it: Mrs. Schmidt was part of Heckel’s work group, too.

+ Press Release

+ “Construction of a Structurally Defined Double-Stranded DNA Catenane”