9.6.19
Rich Nell
Researchers at the University of Arizona (UA) have developed a cellphone-based tool for detecting norovirus in drinking water with what they claim is a highly sensitive and affordable way to detect even extremely low concentrations of the virus.
According to the CDC, norovirus is the most common cause of foodborne illness in the U.S, causing extreme stomach pain, agitation, vomiting and diarrhea. It usually passes in 2-3 days but can lead to dehydration. While causing severe discomfort in developed nations, norovirus leads to death in many underdeveloped parts of the world. Some 200,000 die annually from the infection.
According to this University of Arizona technology review:
A little bit of norovirus – the highly infectious microbe that causes about 20 million cases of food poisoning in the United States each year – goes a long way. Just 10 particles of the virus can cause illness in humans. A team of University of Arizona researchers has created a simple, portable and inexpensive method for detecting extremely low levels of norovirus.
The UA team from the departments of Biomedical Engineering, Biosystems Engineering and Community, Environment and Policy developed a microfluidic chip made from paper with an embedded fluorescent immunoassay consisting of fluorescent polystyrene beads attached to antibodies that bind norovirus. Several beads attached to each viral particle, creating clumps of beads that are luminous enough to be seen with a smartphone microscope.
Pocket-sized cellphone microscopes cost around $200 and clip onto most cellphones. However, the UA team made a customized version including filters to help visualize the clumps of glowing beads. They also created an app to convert illuminated pixels into an estimate of norovirus particles in the sample.
“Paper substrate is very cheap and easy to store, and we can fabricate these chips easily,” said researcher Soo Chung, a UA biosystems engineering doctoral student “The fibrous structure of paper also allows liquid to flow spontaneously without using the pumping systems other chips, such as silicon chips, usually require.”
The microbiology lab equipment typically required to detect norovirus includes microscopes, lasers and spectrometers, which total thousands of dollars to purchase. The UA team wanted a pocket-sized tool that could detect the virus on cruise ships or in a village well. The team plans to develop versions of its microfluidic paper chip for the detection of other disease-causing microbes as well as carcinogens.