A DNA molecule passes through a nanopore in a sheet of molybdenum disulfide, a material that researchers have found to be better than graphene at reading the DNA sequence. Photo courtesy of Amir Barati Farimani
While new techniques have lowered the cost and sped up the process of DNA sequencing over the last few decades, there’s still a good ways to go until every patient will be able to have their genes scanned for disease sequences. One promising technique that has attracted the attention of scientists involves moving the DNA string through a nanopore of a very thin sheet of material. The tiny hole allows the DNA to pass in one direction, driven by an external electric current. As the molecule moves through, the different base pairs that pass through the sheet affect the electric current, giving each letter of the DNA its unique electric signature. The challenge is finding a material that makes this feat practical. Most materials are too thick to have only one base pair located within the nanopore and graphene, a one-atom-thick layer of carbon, tends to make DNA molecules stick to it.
Now scientists at University of Illinois at Urbana-Champaign have identified that nanopores within molybdenum disulfide (MoS2) are excellent at passing DNA through without sticking while being sufficiently thin to only span one base pair at a time. Unlike other materials that have been tried, using molybdenum disulfide produces a unique signal for each letter passing through. Previously, most materials provided only two signals (A/T or C/G) requiring further computational processing to distinguish A from T and C from G. The researchers are planning on further exploring this technology with the goal of significantly lowering the cost of DNA sequencing and making it available to just about everyone.
Study in ACS Nano: DNA Base Detection Using a Single-Layer MoS2…
UIUC press statement: New material could enhance fast and accurate DNA sequencing…