<p>Scientists have developed a new handheld breathalyser test that can non-invasively and accurately diagnose Covid-19, even in asymptomatic individuals, in less than five minutes.</p>.<p>The test, described in the journal ACS Nano, could allow rapid screening of people attending large gatherings, such as conferences and weddings.</p>.<p>Currently, the gold standard for Covid-19 testing is a technique called reverse transcription-polymerase chain reaction (RT-PCR).</p>.<p>However, researchers from Nanyang Technological University, Singapore, noted that RT-PCR is slow, requires an uncomfortable nasopharyngeal swab for sample collection and must be performed in a lab.</p>.<p>The rapid antigen test (RAT) is much quicker but has a higher rate of false negatives and positives, they said.</p>.<p>The team wanted to develop a quick, convenient and accurate breathalyser test that would be suitable for on-site screening of large numbers of people.</p>.<p>The researchers designed a handheld breathalyser that contains a chip with three surface-enhanced Raman scattering (SERS) sensors attached to silver nanocubes.</p>.<p><strong>Also read: <a href="https://www.deccanherald.com/science-and-environment/why-covid-19-patients-lose-their-sense-of-smell-1077642.html" target="_blank">Why Covid-19 patients lose their sense of smell</a></strong></p>.<p>When a person exhales into the device for 10 seconds, compounds in their breath chemically interact with the sensors.</p>.<p>The researchers then load the breathalyser into a portable Raman spectrometer that characterises the bound compounds based on changes to the molecular vibrations of the SERS sensors.</p>.<p>They found that Raman spectra from Covid-positive and -negative people were different in regions responsive to ketones, alcohols and aldehydes, which they used to develop a statistical model for Covid diagnosis.</p>.<p>Scientists have previously developed breathalyser-type tests for Covid-19, which rely on differences in concentrations of volatile organic compounds exhaled by those infected with the coronavirus. However, most of the past tests require bulky, nonportable instruments for analysis.</p>.<p>The team tested the new breathalyser on 501 people in hospitals and airports in Singapore.</p>.<p>The participants were shown by RT-PCR to be negative (85.2 per cent), positive and symptomatic (8.6 per cent), or positive and asymptomatic (6.2 per cent) for the coronavirus.</p>.<p>The breathalyser had a 3.8 per cent false-negative and 0.1 per cent false-positive rate, comparable to RT-PCR tests, but it could be completed on-site in less than five minutes.</p>.<p>The breathalyser could someday be a new tool to reduce the silent spread of Covid-19 in communities, the researchers added.</p>.<p><strong>Check out latest DH videos here</strong></p>
<p>Scientists have developed a new handheld breathalyser test that can non-invasively and accurately diagnose Covid-19, even in asymptomatic individuals, in less than five minutes.</p>.<p>The test, described in the journal ACS Nano, could allow rapid screening of people attending large gatherings, such as conferences and weddings.</p>.<p>Currently, the gold standard for Covid-19 testing is a technique called reverse transcription-polymerase chain reaction (RT-PCR).</p>.<p>However, researchers from Nanyang Technological University, Singapore, noted that RT-PCR is slow, requires an uncomfortable nasopharyngeal swab for sample collection and must be performed in a lab.</p>.<p>The rapid antigen test (RAT) is much quicker but has a higher rate of false negatives and positives, they said.</p>.<p>The team wanted to develop a quick, convenient and accurate breathalyser test that would be suitable for on-site screening of large numbers of people.</p>.<p>The researchers designed a handheld breathalyser that contains a chip with three surface-enhanced Raman scattering (SERS) sensors attached to silver nanocubes.</p>.<p><strong>Also read: <a href="https://www.deccanherald.com/science-and-environment/why-covid-19-patients-lose-their-sense-of-smell-1077642.html" target="_blank">Why Covid-19 patients lose their sense of smell</a></strong></p>.<p>When a person exhales into the device for 10 seconds, compounds in their breath chemically interact with the sensors.</p>.<p>The researchers then load the breathalyser into a portable Raman spectrometer that characterises the bound compounds based on changes to the molecular vibrations of the SERS sensors.</p>.<p>They found that Raman spectra from Covid-positive and -negative people were different in regions responsive to ketones, alcohols and aldehydes, which they used to develop a statistical model for Covid diagnosis.</p>.<p>Scientists have previously developed breathalyser-type tests for Covid-19, which rely on differences in concentrations of volatile organic compounds exhaled by those infected with the coronavirus. However, most of the past tests require bulky, nonportable instruments for analysis.</p>.<p>The team tested the new breathalyser on 501 people in hospitals and airports in Singapore.</p>.<p>The participants were shown by RT-PCR to be negative (85.2 per cent), positive and symptomatic (8.6 per cent), or positive and asymptomatic (6.2 per cent) for the coronavirus.</p>.<p>The breathalyser had a 3.8 per cent false-negative and 0.1 per cent false-positive rate, comparable to RT-PCR tests, but it could be completed on-site in less than five minutes.</p>.<p>The breathalyser could someday be a new tool to reduce the silent spread of Covid-19 in communities, the researchers added.</p>.<p><strong>Check out latest DH videos here</strong></p>