Scientists Build World's Tiniest Thermometer Using DNA

Posted on April 28, 2016

Scientists from the University of Montreal announced they have created the world's tiniest thermometer using DNA. The programmable DNA thermometer is 20,000 times smallest than a human hair.

DNA molecules can unfold when heated. This discovery was first made over 60 years ago. The researchers used this knowledge when developing the tiny nanothermometers.

Prof. Alexis Vallée-Bélisle, senior author of the study, says in a statement, "In recent years, biochemists also discovered that biomolecules such as proteins or RNA (a molecule similar to DNA) are employed as nanothermometers in living organisms and report temperature variation by folding or unfolding. 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."

David Gareau, first author of the study, says, "DNA is made from four different monomer molecules called nucleotides: nucleotide A binds weakly to nucleotide T, whereas nucleotide C binds strongly to nucleotide G. 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."

The researchers say the nanoscale thermometers open up new avenues in the emerging field of nanotechnology and could help us better understand molecular biology. Vallée-Bélisle points out that we know the temperature of the human body but we don't know whether or not there is "a large temperature variation at the nanoscale inside each individual cell." The nanothermometers could be used in very small devices that monitor local temperature at the nanoscale.

The research paper on the nanothermometers was published here in the journal, Nano Letters.