Scientists at the University of California, San Diego have developed a sensor capable of detecting single nucleotide polymorphisms (SNPs), a type of DNA mutations. The graphene chip may soon allow clinicians to perform cancer screenings, monitor infections, and offer more capabilities for personalized medicine, among other possibilities. The researchers envision a future implant based on their technology that will be able to spot specific mutations and wirelessly send a warning signal to a monitor outside the body.
The prototype device relies on a DNA probe, a double stranded snippet of DNA that has the nucleotide sequence being searched for, placed within a graphene field effect transistor. The two strands of the helix are slightly different, one of them containing a sequence that doesn’t quite match the other’s. This makes the bond between the two strands less than perfect and allows another, better matching strand, to displace the weakly connected strand and stick to the other. Once a strand that has the matching SNP performs this trick, the graphene detector recognizes that a match has been made and an electronic signal is produced notifying of the event.
The researchers are pointing out to the technology will produce very few false positives, since a perfect match has to exist for a strand on the DNA probe to be popped off and replaced by another. This has been a problem for single strand detectors which attract a much larger subset of DNA strings that need only to bind weakly to the target string.
There’s more work to be done before this technology will see clinical use, but the fundamentals have been established and which will now need to be transferred from the laboratory to the clinic.
Study in Proceedings of the National Academy of Sciences: Highly specific SNP detection using 2D graphene electronics and DNA strand displacement…
Via: UCSD…
