Could the molecule of life become the molecule of electronics? Scientists have taken another step towards making it a reality. Cathal O'Connell reports.
The patterns of DNA base pairs, which code our genes, can also be used to tune the flow of electricity, American researchers have found.
The work could one day lead to DNA-based electronics, made of components much tinier than those squeezed on to current silicon-based computer chips.
In Nature Chemistry today, a team led by Nongjian Tao at Arizona State University describe how the pattern of bases (A, C, G or T) can make electricity flow as smoothly through DNA as through a metal wire, or in hopping steps more like semiconductors.
The insight relies on exploiting the quantum nature of the electron – hence determining whether electrons act like waves or particles as they move through a DNA strand.
For decades, engineers have been cramming more and more circuit elements on to computer chips by making the individual components, such as the transistor “switches”, smaller.
The problem is, this shrinkage can’t go on forever. Eventually, you reach a limit where neighbouring transistors interfere with one another. To go beyond silicon, scientists are looking towards making electronics from individual molecules.
And DNA is one of the most promising molecules for building electronics, being first discovered by nature 3.8-odd billion years ago.
The key advantages of DNA are its stability and the way it can be programmed to assemble into predesigned structures. In 2009, for example, scientists used DNA as a kind of circuit board for assembling electronic components six nanometres apart – much tinier than current silicon processing allows.
DNA also has interesting electrical conductivity, although its measured properties have varied in a somewhat mystifying way.
In 2014, for example, scientists developed DNA-based wires showing it can conduct electricity a bit like metals.
