When doctors want to see if someone has a certain illness, they may check the patient's blood or urine for the DNA of a specific virus or bacteria, or for a mutated version of the person's own DNA. A new device should make doing so much, much faster and easier.
One of the problems with current electronic DNA-detecting techniques lies in the fact that initially, the target DNA might only be present in low concentrations. As a result, the electrostatic and electrochemical signals produced by other molecules in the blood or urine sample may drown out the telltale signals produced by the DNA.
That's why a team of scientists at the University of Massachusetts Amherst created the new sensor, which is claimed to be 100 times more sensitive than existing technologies.
The compact, portable, inexpensive device incorporates a graphene transistor to which all the DNA strands in a sample are tethered. When those strands are exposed to an alternating electric field, they oscillate in place. If the sensor detects the unique oscillation frequency which is already known to be produced by the target DNA, it lets the user know that the DNA is present in the sample.
Not only does this technique detect even very low concentrations of the DNA, but it also delivers results within a matter of minutes – by contrast, existing methods may take weeks or even months.
It is hoped that once developed further, the technology could have other potential applications.
"The nano-mechanoelectrical approach can be also integrated with other bioengineering technologies, like CRISPR, to elucidate nucleic acid signaling pathways, comprehend disease mechanisms, identify novel drug targets and create personalized treatment strategies, including microRNA-targeted therapies," said the lead scientist, Asst. Prof. Jinglei Ping.
A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences.
