A saliva test that instantly detects coronavirus with lasers could be available within a year, scientists say.

Researchers are developing a laser sensor that can pick up the disease at the earliest point of infection from a saliva or nasal swab in minutes.

They say the non-invasive optical biosensor demonstrator will pick up Covid-19 in humans as soon as it is present in the body.

Having already created six working laboratory demonstrators for other applications, the research team says the technology still needs further adaptation and testing but could be available in a year at the latest.

It was originally developed to look for bacterial infections or cancer biomarkers, the detector uses photonics – technology that manipulates light – to identify infections in patients with a small amount of the virus.

Researchers say the real-time diagnosis with high specificity from a low concentration sample, the sensor is much more reliable than the coronavirus rapid-test, “finger-prick” kit which detects if a person has had the coronavirus before and has since recovered.

Calling themselves CONVAT and co-ordinated at ICN2 – the Catalan Institute of Nanoscience and Nanotechnology, Spain – the researchers have tested the demonstrators on patients’ samples provided by hospitals in Spain.

Project co-ordinator, Professor Laura Lechuga said: “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.

“We are currently integrating all the instrumentation in a portable 25x15x25 cm box with a tablet control.

“At present, our detector is user-friendly, with the preparation being only technical expertise required, and could be widely deployed for GPs or nurses to test patients.

“Our nanosensor is capable of detecting RNA strands which will fully identify the new coronavirus.”

Chairman of the Photonics21 Healthcare Workgroup, Dr Jurgen Popp, said: “The CONVAT team are working round the clock to develop a rapid, non-invasive test for coronaviruses.

“The ability to spot this terrible virus quickly will contribute to the worldwide effort in fighting 2019-nCoV and highlights yet another success for photonics and light technologies.”

Funded by Horizon 2020, the European Commission’s scientific research initiative, the scientists started work on their detector at the start of March, in response to the pandemic.