A team at the University of Illinois at Urbana-Champaign has developed a DNA net system that can ensnare Sars-CoV-2 and bind to the notorious spike protein. The nets contain aptamers that bind the spike protein and emit an intense fluorescent signal once they’re bound together to the protein. This signal can be easily measured using a handheld fluorimeter. The technology provides a rapid and accurate way to test for the presence of the virus, and the researchers report that it has similar sensitivity as the current gold-standard test, PCR. However, the technology is not just envisaged as diagnostic. The nets can bind and disable the virus, suggesting that they may also have therapeutic applications. While the pandemic may be winding down, the risk of new variants is ever present. Moreover, no-one knows when the next pandemic will arise, so the technologies we develop now will doubtless help us when new viruses emerge. This latest technology could do just that, and it has the potential to be both diagnostic and therapeutic. “This platform combines the sensitivity of PCR and the speed and low cost of antigen tests,” said Xing Wang, one of its developers. “We need tests like this for a couple of reasons. One is to prepare for the next pandemic. The other reason is to track ongoing viral epidemics — not only coronaviruses, but also other deadly and economically impactful viruses like HIV or influenza.” The DNA nets created by these researchers can rapidly and inexpensively provide Sars-CoV-2 detection. The system involves a user mixing a patient sample with the DNA nets, and then employing a handheld fluorimeter to detect if the aptamers present have bound to the viral spike protein. “I had this idea at the very beginning of the pandemic to build a platform for testing, but also for inhibition at the same time,” Wang said. “Lots of other groups working on inhibitors are trying to wrap up the entire virus, or the parts of the virus that provide access to antibodies. This is not good, because you want the body to form antibodies. With the hollow DNA net structures, antibodies can still access the virus.” The system may be suitable for point-of-care use, as it does not require any specialized equipment and is relatively inexpensive, costing approximately $1.26 per test. The technology can also be easily adapted to help detect other viruses. “Another advantage of this measure is that we can detect the entire virus, which is still infectious, and distinguish it from fragments that may not be infectious anymore,” said Wang. “This not only gives patients and physicians better understanding of whether they are infectious, but it could greatly improve community-level modeling and tracking of active outbreaks, such as through wastewater.” Source
