Scientists have built the tiniest antenna ever made – just five nanometers in length. Unlike its much larger counterparts we're all familiar with, this minuscule thing isn't made to transmit radio waves, but to glean the secrets of ever-changing proteins.
The nanoantenna is made from DNA, the molecules carrying genetic instructions that are around 20,000 times smaller than a human hair. It's also fluorescent, which means it uses light signals to record and report back information.
Part of the innovation with this particular antenna is the way in which the receiver part of it is also used to sense the molecular surface of the protein it's studying. That results in a distinct signal when the protein is fulfilling its biological function.
"Like a two-way radio that can both receive and transmit radio waves, the fluorescent nanoantenna receives light in one color, or wavelength, and depending on the protein movement it senses, then transmits light back in another color, which we can detect," says chemist Alexis Vallée-Bélisle, from the Université de Montréal (UdeM) in Canada.
Specifically, the job of the antenna is to measure the structural changes in proteins over time. Proteins are large, complex molecules that carry out all kinds of essential tasks in the body, from supporting the immune system to regulating the function of organs.