They could be used to enable rapid screening of people attending large gatherings, such as conferences and weddings. Even those who are asymptomatic can still transmit Covid-19 to others, making it important to identify and isolate them until they are no longer contagious.
The “gold standard” for Covid-19 testing is a technique called reverse transcription-polymerase chain reaction, commonly known as PCR tests. But this technique is typically slow, requires an uncomfortable nasopharyngeal swab for sample collection, and must be performed in a lab.
The rapid antigen test is much quicker but has a higher rate of false negatives and positives. Scientists have also developed breathalyser-type tests for Covid-19, which rely on differences in concentrations of volatile organic compounds exhaled by those infected with the coronavirus, but most require bulky, nonportable instruments for analysis.
Now a team of researchers from Nanyang Technological University...