Transitioning to home working had its challenges for us all, but when your job involves researching biological applications for nanotechnology, those trials are a little more complicated than juggling the household’s broadband usage. So barred from his lab, you might reasonably expect the research by organic chemist Vittorio Saggiomo, from the Bionanotechnology group at Wageningen University & Research in the Netherlands, to have come to a grinding halt.
But Saggiomo is a creative, imaginative type, and so he began to wonder if he could turn common household appliances to good use in the fight against COVID-19. More specifically, could he create a cheap, highly sensitive home test for the virus? It turns out he could. His team has now posted the idea on a preprint server, ChemArxiv. The paper is yet to be reviewed by other scientists.
At the moment, there are two main types of COVID-19 test: the PCR test and the lateral flow test (LFT). The gold-standard PCR test checks for the presence of the virus by detecting its genetic material known as RNA. But there are vanishingly small amounts of viral material in a swab, so the material has to be converted into DNA and amplified before it can be detected. And this is achieved by the “polymerase chain reaction”, which is what PCR stands for.
The process involves repeated cycling through a range of temperatures between 50°C and 90°C. During each cycle, the amount of DNA doubles, so after 30 cycles over a billion copies of the viral material can be created from just one strand of starting material. The amplified material is then detected with fluorescent labels that attach themselves to the viral DNA sequences.
As such, PCR is a highly sensitive technique, but it needs specialist materials and equipment to perform. This is why the tests are sent off to a lab, and it takes a day or two to get the result.
The second common test is the lateral flow test (LFT). These work by detecting fragments of viral protein shells. Embedded within the strips of the LFTs are antibodies that bind to the virus. These antibodies are labelled with tiny gold particles, which appear red, allowing you to see them on the test device. The labelled antibodies accumulate on distinct bands on the LFT depending on whether the virus is present or not.