DNA Nanothermometers
DNA helped physicists create a nanothermometer 20 thousand times thinner than a hair
Physicists from Canada have created an unusual nanopribor from a short DNA strand, which is a miniature thermometer capable of measuring the slightest fluctuations in temperatures and at the same time having dimensions 20 thousand times smaller than a human hair, according to an article published in the journal Nano Letters (Gareau et al., Programmable Quantitative DNA Nanothermometers).
"Living organisms use various biomolecules, such as proteins or RNA, to measure temperatures and react to it. Using them as an example and a subject of inspiration, we have created several DNA structures that are assembled and disassembled at strictly defined temperatures," said Alexis Vallee–Belisle from the University of Montreal (in a press release Chemists use DNA to build the world's tiniest thermometer - VM).
As the scientist notes, DNA is an ideal material for creating such bio-thermometers for the reason that the properties of its individual "letters" have been well studied in recent years, and biologists have learned to control their behavior quite well.
For example, biochemists are well aware of the strength with which nucleotides A and T and G and C are linked to each other in the DNA chain, which allows them, by combining different numbers of these letters, to assemble molecules that will break into halves at a certain temperature. By connecting protein molecules to such DNA chains that glow when they decay, scientists have obtained ultra-sensitive and miniaturized nano-thermometers.
Such "thermometers", as explained by Valli-Belisle and his colleagues, are able to work at temperatures from 25 to 90 degrees and feel temperature differences not exceeding hundredths of a degree Celsius. They do not break down when used and are able to work for an extremely long time both inside the body and in a neutral chemical environment.
Graph from an article in Nano Letters
The miniature dimensions of these thermometers, according to the biologist, will help realize the dream of many scientists – to measure how the temperature changes inside human and animal cells. Such observations, as Valli-Belisle hopes, will help us understand which parts of the cells are heated the most when working, and find out whether they overheat under high load. In addition, such DNA-based sensors will help engineers developing microchips to find overheating points and make microchips more economical and productive.
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27.04.2016