Ultrasensitive laser test can quickly detect coronavirus in saliva

7 Apr 2020

A Convat researcher working on the coronavirus testing kit. Image: Convat

To meet an urgent need for new coronavirus testing equipment, researchers have developed one solution that uses ultrasensitive lasers.

European researchers have joined forces to develop a test that can identify minute traces of the coronavirus from someone’s saliva more reliably than some existing test kits. This new rapid, non-invasive optical biosensor was originally created to look for bacterial infections or cancer biomarkers.

The test was developed by a team named Convat, coordinated by the Catalan Institute of Nanoscience and Nanotechnology in Spain, which has tested the kit on samples from patients at Vall D’Hebrón Hospital in Barcelona and several other hospitals.

It uses ultrasensitive lasers to look at the ‘binding’ of the coronavirus molecules to the sensor surface that produces a new signal when the virus is present. Since the bioreceptors on the sensor surface are specifically ‘tuned’ to a particular antigen of the virus, only the coronavirus molecules are captured along the sensor.

Once a sample is prepared and is in place, the device confirms a positive or negative for coronavirus instantaneously. However, it could take up to 30 minutes to allow for preparation time and analysis of the sample.

Exploiting light for our benefit

All of the equipment developed as part of the testing kit is currently being shrunk into a single, small device that can be controlled by a tablet.

“With thousands of deaths worldwide, we are in urgent need of a rapid new testing kit that is accurate, highly sensitive, non-invasive and cheap to produce,” said project coordinator Prof Laura Lechuga.

“At present, our detector is user-friendly, with the preparation being [the] only technical expertise required, and could be widely deployed for GPs or nurses to test patients. Photonics is renowned for its rapid, stand-off and clean detection capabilities, so it made perfect sense to develop a device that exploited light amid this terrible pandemic.”

The Convat team was quickly assembled to meet the European Commission’s urgent call for research to tackle the spread of the coronavirus. According to Lechuga, it took eight 12-hour days to put together the team and write a successful funding proposal.

With six working demonstration devices developed so far, the team said it still needs to further test and develop the technology. It hopes to have a final concept ready for clinical use within the next year.

Colm Gorey was a senior journalist with Silicon Republic