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How Do You Make Nano Robots out of DNA and Gold, Ms Liu?

By Nadine Querfurth

A mini robot that is made of the same material as our DNA, that can be controlled by light and that can move within a cell ? This is no longer a future vision – the Chinese physicist Laura Na Liu has built one in nano format. 

Laura Na Liu
Laura Na Liu (Photo: Humboldt Foundation / David Matthiessen)

In her research, Liu delves into the realms of the tiniest things: on the nanometre scale. The main component of her smallest machine is just a ten-thousandth of a human hair in diameter. It is composed of bundles of coiled DNA which are joined together by a kind of hinge, rather like scissor blades that can be opened and closed.

“It is crucial that the process can be reversed,” says Liu. In order to visualise the opening and closing of the hinge, the physicist turns to nanoplasmonics. She has managed to equip the DNA bundles with tiny gold particles and excite them with UV light. The gold particles then begin to oscillate and emit optical signals which Liu can measure precisely. “Now the nano machines have to function just as well in living cells as they do in the test tube because, figuratively speaking, a cell is stuffed full of ballast.”

“It is crucial that the process can be reversed,” says Liu. In order to visualise the opening and closing of the hinge, the physicist turns to nanoplasmonics. She has managed to equip the DNA bundles with tiny gold particles and excite them with UV light. The gold particles then begin to oscillate and emit optical signals which Liu can measure precisely. “Now the nano machines have to function just as well in living cells as they do in the test tube because, figuratively speaking, a cell is stuffed full of ballast.”

published in Humboldt Kosmos 106/2016

The Sofja Kovalevskaja Award Winner Professor Dr Laura Na Liu  conducts research at the Max Planck Institute for Intelligent Systems in Stuttgart and holds a professorship in the Kirchhoff Institute for Physics at Heidelberg University.