Scientists at Canada’s University of Montreal have devised an incredibly advanced, programmable DNA thermometer 20,000 times smaller than a single human hair. Recently published in the Nano Letters journal, the breakthrough could enhance our understanding of natural and human-designed nanotechnologies, by allowing researchers to accurately measure temperature in nanoscale.
According to the scientists, DNA molecules containing genetic information are found to unravel when heated to a particular temperature. Scientific research in recent years has revealed that biomolecules, such as RNA, double as nanothermometers in organisms, reporting temperature changes through folding and unfolding. Speaking about the breakthrough, Alexis Vallée-Bélisle, the paper’s senior author, said:
Inspired by those natural nanothermometers, which are typically 20,000x smaller than a human hair, we have created various DNA structures that can fold and unfold at specifically defined temperatures.
One of the many advantages of using DNA molecules as nanoscale thermometers is that their chemistry is relatively well-known and programmable. DNA, in general, comprises of four monomer molecules, known as nucleotides. These include nucleotide A, which is loosely bound to nucleotide T, and nucleotide C, which binds strongly with nucleotide G. Arnaud Desrosiers of the University of Montreal explained:
Using these simple design rules we are able to create DNA structures that fold and unfold at a specifically desired temperature. By adding optical reporters to these DNA structures, we can therefore create 5 nm-wide thermometers that produce an easily detectable signal as a function of temperature.
According to the team, the technology could usher in new developments in the field of nanotechnology. This could in turn improve our understanding of molecular biology. As Alexis Vallée-Bélisle points out, one of the major unanswered questions in molecular biology pertains to the human body temperature. While we already know that our body temperature is maintained at 37 degrees Celsius, biologists are currently trying to see if there is a large temperature variation at the cellular level.
Additionally, the researchers are hoping the new technology would help solve another mystery, as to whether naturally-occurring nanomotors and nanomachines also exhibit overheating when functioning high rate. Alexis Vallée-Bélisle added:
In the near future, we also envision that these DNA-based nanothermometers may be implement in electronic-based devices in order to monitor local temperature variation at the nanoscale.