Researchers have developed a prototype, handheld “breathalyzer” that can sensitively and accurately diagnose COVID-19, even in asymptomatic individuals, in less than 5 minutes.
The handheld breathalyzer designed by researchers contains a chip with three surface-enhanced Raman scattering (SERS) sensors attached to silver nanocubes. When a person exhales into the device for 10 seconds, compounds in their breath chemically interact with the sensors. Then, the researchers load the breathalyzer into a portable Raman spectrometer that characterizes the bound compounds based on changes to the molecular vibrations of the SERS sensors.
The report was recently published in American Chemical Society Nano.
The team of researchers 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. They tested the breathalyzer on 501 people in hospitals and airports in Singapore, who were shown by RT-PCR to be negative (85.2%), positive and symptomatic (8.6%), or positive and asymptomatic (6.2%) for the coronavirus.
The method had a 3.8% false-negative and 0.1% false-positive rate, comparable to RT-PCR tests, but it could be completed on-site in less than 5 minutes. The breathalyzer could someday be a new tool to reduce the silent spread of COVID-19 in communities, the researchers say.
The authors acknowledge funding from the National Medical Research Council, Singapore, A*STAR Singapore, the Max Planck Institute-Nanyang Technological University Joint Lab and Nanyang Technological University.
Featured image: A SERS-based breathalyzer can distinguish volatile organic compounds in the breath of COVID-positive people in less than 5 minutes. Photo: Shi Xuan Leong and Yong Xiang Leong, Nanyang Technological University