Quick COVID breathalyzer could allow mass screening in public places


Date:
February 2, 2022
Source:
American Chemical Society
Summary:
Researchers have developed a prototype 'breathalyzer' that can
sensitively and accurately diagnose COVID-19, even in asymptomatic
individuals, in less than 5 minutes.



FULL STORY ========================================================================== According to experts, bringing an end to the pandemic will require 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. Now, researchers reporting in ACS Nano have developed
a prototype "breathalyzer" that can sensitively and accurately diagnose COVID-19, even in asymptomatic individuals, in less than 5 minutes.


========================================================================== Currently, the "gold standard" for COVID-19 testing is a technique called reverse transcription-polymerase chain reaction (RT-PCR), which is 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 breathalyzer-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. Xing Yi Ling and colleagues wanted to develop a quick,
convenient and accurate breathalyzer test that would be suitable for
on-site screening of large numbers of people.

The researchers designed a handheld breathalyzer that 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 team 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.

========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Shi Xuan Leong, Yong Xiang Leong, Emily Xi Tan, Howard Yi Fan Sim,
Charlynn Sher Lin Koh, Yih Hong Lee, Carice Chong, Li Shiuan Ng,
Jaslyn Ru Ting Chen, Desmond Wei Cheng Pang, Lam Bang Thanh Nguyen,
Siew Kheng Boong, Xuemei Han, Ya-Chuan Kao, Yi Heng Chua, Gia
Chuong Phan-Quang, In Yee Phang, Hiang Kwee Lee, Mohammad Yazid
Abdad, Nguan Soon Tan, Xing Yi Ling. Noninvasive and Point-of-Care
Surface-Enhanced Raman Scattering (SERS)-Based Breathalyzer for
Mass Screening of Coronavirus Disease 2019 (COVID-19) under 5
min. ACS Nano, 2022; DOI: 10.1021/acsnano.1c09371 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220202143112.htm

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