Researchers at the University of Florida and Chiao Tung National University of Taiwan have developed a microfluidic device that can detect the SARS-CoV-2 spike protein in a saliva sample in a second. The electrochemical device uses antibodies against the ear protein to detect the virus and could allow ultrafast testing of COVID-19.
The evidence remains a cornerstone in our fight against COVID-19. Although the pandemic has calmed down in some regions of the world, others are still severely affected and it will be a long time before robust testing regimes are no longer required. The current gold standard is the PCR test, which is a leader in terms of accuracy but requires highly trained personnel and specialized laboratory equipment, which result in significant lag times between sample collection and obtaining. of results.
As society opens up, faster testing methods may have a place in controlling the spread of the virus, and researchers have not been disappointed in their efforts to develop these technologies. The latter device is based on the experience of researchers who have previously developed technologies to detect biomarkers of heart attacks, cerebrospinal fluid leaks and the Zika virus.
Surprisingly, the new COVID-19 test has an almost instantaneous detection time, which provides a positive or negative result in just 1 second. “This could alleviate the slow response time problems of the COVID-19 tests,” Minghan Xian, a researcher involved in the study, said in a press release.
Viral detection occurs in a gold electrode filled with antibodies against the viral spike protein, which can be charged with a sample, such as saliva. Binding of the Spike protein to the electrode will change the electrical charge passing through it and allow the device to detect the virus. The entire electrode is included in a disposable test strip that the user connects to the phone to perform the analysis.
“Our biosensor strip is similar to commercially available glucose test strips, with a small microfluidic channel at the tip to introduce our test fluid,” Xian said. “Within the microfluidic channel, a number of electrodes are exposed to the fluid. One is coated with gold and the relevant COVID antibodies are attached to the gold surface by a chemical method.
Because the level of spike protein in a sample may be small, the test amplifies the signal to allow for more accurate detection. “Our sensor system, a circuit board, uses a transistor to amplify the electrical signal, which then becomes a number on the screen,” Xian added. “The magnitude of this number depends on the concentration of antigen, the viral protein, present in our test solution.”
Study a Journal of Vacuum Science & Technology B: Rapid detection of SARS-CoV-2 virus using single-use cartridge strips and a semiconductor-based biosensor platform
Via: Editorial AIP