Researchers from the DBT-National Institute of Animal Biotechnology (NIAB) in Hyderabad have developed a highly sensitive portable device that can rapidly detect minute traces of the novel coronavirus in human saliva1.
The device can directly detect a specific protein of the coronavirus, even when present in very low concentrations in saliva, within 30 seconds.
The device selectively detects the virus with no cross reactivity with other viruses. It has been found to be stable up to four weeks with no change in its efficiency in detecting the virus.
The scientists, led by Sonu Gandhi, from the DBT-NIAB designed the biosensor caled eCovSens. This biosensor contains a carbon electrode and a specific antibody that only binds to the spike protein, a protein found in the outer layer of the virus. It also has a display, a processor and an amplifier.
When this device is exposed to saliva samples spiked with traces of the spike protein, it generates an electrical signal. This signal is then amplified, processed and converted from analogue to digital reading and displayed on the device screen. If the device is connected to a mobile or a computer via bluetooth, the readings can reflect on their screens.
The device can detect very low concentrations of the virus and it doesn’t need isolating the viral RNA that requires extra step, machines and time. The researchers will now validate these results by testing saliva samples isolated from COVID-19 patients.
1. Mahari, S. et al. eCovSens-ultrasensitive novel in-house built printed circuit board based electrochemical device for rapid detection of nCovid-19. Preprint. (2020) doi:10.1101/2020.04.24.059204