Researchers from St. Petersburg Academic University in Russia report in a paper posted to arXiv that they've been able to detect and distinguish synthetic DNA oligonucleotides based on how they vibrate.
"[Andrey] Chernev and co’s idea is based on the way these molecules resonate. They say that the sequence of bases in an oligonucleotide determines the way in which the strand resonates at frequencies in the terahertz range," the arXiv Blog notes. "Their idea is to capture a single oligonucleotide in a cavity filled with terahertz waves that stimulates this resonant behavior."
To detect the oligonucleotides, the researchers relied on the interaction of a silicon nanodsandwich with the nucleic acids that are then deposited on it. The nanosandwich includes a silicon quantum well, the edge channels of which are a source of terahertz radiation. Then by measuring the molecule's resonant modes, the researchers say they could determine its spectra and its sequence.
Chernev and his colleagues tested their approach out using two synthetic oligonucleotides, a 50-mer and a 100-mer, and could tell the difference between the two oligonucleotides.
As the arXiv Blog notes, a library of signatures associated with each oligonucleotide would be needed in order to identify more complicated sequences, something that Chernev and his colleagues are beginning to build.
"That is an interesting approach," the blog adds. "But this is a crowded area in which lots of good ideas are competing to become the standard technique for identifying the molecules of life quickly and cheaply."