According to Bingqian Xu, an associate professor at the University of Georgia: “For 50 years, we have been able to place more and more computing power onto smaller and smaller chips, but we are now pushing the physical limits of silicon. If silicon-based chips become much smaller, their performance will become unstable and unpredictable.”
Xu says DNA’s predictability, diversity and programmability make it a leading candidate for the design of functional electronic devices using single molecules. In a paper published in Nature Chemistry, the researchers described using a single molecule of DNA to create the world’s smallest diode.
Xu and a team of graduate research assistants at UGA isolated a specifically designed single duplex DNA of 11 base pairs and connected it to an electronic circuit only a few nanometres in size. After the measured current showed no special behaviour, the team intercalated a molecule of coralyne into a specific location in the DNA. Having done that, the team found the current flowing through the DNA was 15 times stronger for negative voltages than for positive voltages.
“Our discovery can lead to progress in the design and construction of nanoscale electronic elements that are at least 1000 times smaller than current components,” Xu claimed.
The team now plans to construct further molecular devices and to enhance the performance of the molecular diode.
