Programmable molecular machines are getting closer

Two potential applications already demonstrated

"With our design, we were able to show that a DNA-based switch can not only be controlled quickly and precisely, but is also exceptionally long-lived," says Prof. Friedrich Simmel, Professor of Physics of Synthetic Biological Systems at the TUM School of Natural Sciences. "This makes it more realistic to use DNA-based components as functional elements of future molecular machines."

The research team has already tested two possible applications. In one experimental setup, the switch was coupled to gold nanorods. In this way, an optical signal could be turned on and off depending on the position of the switch. In a second experiment, the team used the switch to alternately expose or shield a binding site for other DNA strands. This made it possible to control the speed of this binding process.

The study thus does more than introduce a single new nanoscale component. It also provides a basis for systematically investigating durability, wear, and potential failure modes of molecular switches. First author Florian Rothscher says: "In the future, such electrically controllable DNA systems could be of interest for molecular information processing, for optical nanodevices, and for the targeted control of chemical reactions."

The experiments were carried out under controlled laboratory conditions and in specialized measurement setups. The results show that the concept works reliably under these conditions. However, further development steps will be necessary before potential technical applications outside such laboratory environments become feasible.