Researchers in Singapore have developed a prototype breathalyzer that is claimed to be as effective as PCR testing in identifying people with COVID-19. The system is over 95 percent accurate at detecting both symptomatic and asymptomatic SARS-CoV-2 infections, delivering results in less than five minutes.

PCR (polymerase chain reaction) technology is the most accurate way to test for SARS-CoV-2 but it involves expensive and complicated lab equipment, which often mean it can take hours, or even days, to get a test result back. Rapid antigen testing, on the other hand, is a much faster way to test for the presence of the virus but it has accuracy limitations, often delivering inconsistent results.

Attempting to address the need for a fast, easy and accurate COVID-19 test, researchers in Singapore have reported on the success of a breathalyzer prototype designed to deliver results in less than five minutes. It comes after a number of researchers have presented compelling blueprints for breath-based COVID-19 diagnostics over the last two years.

These COVID breathalyzers don’t specifically detect the virus, but instead are designed to identify patterns of volatile organic compounds (VOCs) that correspond with a SARS-CoV-2 infection. Particular patterns of molecules such as aldehydes and ketones have been linked with COVID-19 and this makes it feasible for exhaled breath to serve as an effective way to quickly screen lots of people.

The challenge in developing an effective COVID-19 breathalyzer has been making the technology portable enough so the test is viable in real-world contexts. Many hypothetical COVID breath tests require bulky lab equipment such as gas chromatographs, meaning the test could never be widely deployed.

The new device uses a technology called Raman spectroscopy, which allows for the identification of certain patterns of molecules with great accuracy. And most importantly, there are relatively affordable portable Raman spectrometers that could allow for large-scale breathalyzer screening in real-world environments.

The specific breathalyzer device contains a trio of surface-enhanced Raman scattering (SERS) sensors attached to silver nanocubes. Only 10 seconds of breath is needed for the sensors to collect a sample. The breathalyzer is then loaded into a small portable spectrometer that delivers results in under five minutes.

The prototype device was recently tested on 501 people who were all also tested by PCR. The impressive results showed a 0.1 percent false positive rate and a 3.8 percent false negative rate. This is equal to the accuracy seen in lab PCR testing.

More work is needed to validate these results and commercialize the technology, however, the novel breathalyzer is one of many new technological innovations emerging to make COVID-19 testing easy and portable, from a smartphone testing kit to a clip-on exposure monitor.

The new study was published in the journal ACS Nano.

Source: American Chemical Society