DNA is the fundamental molecule for life on Earth, but it might soon become a key component in the construction of nanoelectronic devices as well.
According to researchers from Duke University and Arizona State University, specific DNA sequences can become electron "highways," allowing electricity to more easily flow through the strand.
Electrons are thought to move in two ways along DNA molecules: For long distances, they hop from one base to the other, while for short distances they are more like a wave, smeared out across multiple molecular bases.
In the study, published in Nature Chemistry, the researchers have shown that under certain conditions, the wave-like behavior can be used for longer distances as well.
"In our studies, we first wanted to confirm that this wave-like behavior actually existed over these lengths," lead author Chaoren Liu said in a statement. "And second, we wanted to understand the mechanism so that we could make this wave-like behavior stronger or extend it to even longer distances."
DNA is a double helix made up of four different bases called nucleotides that are chained up in a specific sequence. Portions of the sequence are what we interpret as genes, which contain the instructions our cells need to construct proteins and perform specific functions.
The scientists used computer simulations to model how different sequences would transfer electrons. They discovered that a sequence that alternates blocks of five guanine bases on opposite strands of DNA created the best set-up for the long-range transmission of electrons.
"We can think of the bases being effectively linked together so they all move as one," Liu said. "This helps the electron be shared within the blocks."
There are several consequences from this research. These findings can be used to construct new types of nanoelectronic devices with DNA as wires, it can help understand the role of electron transport in biological systems, and it can even be used in electric currents to find damaged genes.
"This theoretical framework shows us that the exact sequence of the DNA helps dictate whether electrons might travel like particles, and when they might travel like waves," said David Beratan, professor of chemistry at Duke University and leader of the Duke team. "You could say we are engineering the wave-like personality of the electron."
