The work, which has
been published in the American Chemical Society journal
, is also being presented at the ACS Fall 2019
National Meeting & Exposition on 25-29 August, 2019 in San Diego, USA.
, stomach pain, and abdominal cramps.
include fever, headache
and body ache. It is spread by contaminated food and
water, particularly seafood such as shellfish
. It can also be spread
by coming into contact with an infected person. Although usually associated with cruise liners,
outbreaks can occur in communities and spread rapidly through the water supply.
Importantly, as few
as 10 norovirus particles can cause disease in humans and is responsible for over
20 million cases of food poisoning every year in the US.
responsible for approximately 200,000 deaths annually across the globe.
The study was led
by Dr. Jeong-Yeol Yoon, PhD, who is the Associate Department Head for
Biomedical Engineering Graduate Affairs and Professor of Biomedical
Engineering; Professor of Biosystems Engineering; and Professor of Chemistry
& Biochemistry at the University of Arizona, Tucson, USA.
Other key team
members included Soo Chung, a PhD student in Biosystems Engineering in Yoon's
lab and Professor Kelly A. Reynolds, PhD, who is a Professor of Public Health
and Chair of the Department of Community, Environment and Policy at the Mel and
Enid Zuckerman College of Public Health, University of Arizona, Tucson, USA.
What are the Disadvantages of Conventional
conventionally tested in a laboratory setting, using a variety of high-end,
expensive instruments, including microscopes, spectrometers, and lasers. The
high cost of these types of equipments is a
major disadvantage. Moreover, these cannot be used in field-settings for
testing norovirus, such as in cruise liners or municipal water tanks.
What are the Advantages of the New Technology?
As opposed to
expensive conventional testing methods, the new technology uses inexpensive
materials such as paper-based microfluidic chips and a smartphone, which costs
less than USD 50. A major advantage of paper is that it is very cheap and easy
to store, thereby making it relatively easy to fabricate the chips. Moreover,
as paper is fibrous in nature, it permits the smooth flow of liquid
spontaneously without the need for a pumping system that is required for
conventional silicon chips.
is that the new method detects norovirus by means of fluorescent beads, which
attach to the virus surface and can be easily quantitated by counting the
fluorescent spots. This alleviates the need for measuring light intensity,
which results in background light scattering due to the opaque and porous
nature of the paper, thereby making it difficult to detect minute
concentrations of the virus.
"You don't have to be a scientist or an engineer to
run the device,"
says Yoon. "Analysis
will be done automatically by the smartphone app, so all you have to worry
about is loading a sample of water onto the chip."
How is Norovirus Tested Using the New Technology?
The test involves
adding a tiny drop of potentially contaminated water at one end of the
paper-based microfluidic chip. At the other end of the chip, microscopic
polystyrene beads tagged with fluorescent norovirus-specific antibodies are
added. If norovirus is present in the water sample, the antibodies attach to
the virus and cause clumping or aggregation of the polystyrene beads.
emitted from the aggregated clump of polystyrene beads can be detected and
photographed by the smartphone microscope. The smartphone uses an app developed
by the researchers to count the illuminated pixels in the image. Each
fluorescent pixel represents a clump of beads attached to a single norovirus
particle. Therefore, the total number of pixels represents the total number of
norovirus particles present in the sample, which makes quantitation very simple
The research team is hopeful that the new technology can be
tweaked so that norovirus infections can be detected early.
smartphone platform could be expanded to detect other infectious pathogens, as
well as hazardous chemicals
"Advances in rapid monitoring of human viruses in
water are essential for protecting public health,"
Reynolds concludes. "This rapid, low-cost water quality
monitoring technology could be a transformational tool for reducing both local
and global disease burdens."
The research was
funded by the National Science Foundation Water and Environmental Technology
(WET) Center, which is an Industry/University Cooperative Research Center
(I/UCRC) located at the University of Arizona. Funding was also provided by
Tucson Water, which is the Water Department of the City of Tucson.
- Smartphone-Based Paper Microfluidic Particulometry of Norovirus from Environmental Water Samples at the Single Copy Level - (https://pubs.acs.org/doi/10.1021/acsomega.9b00772)