Researchers Develop Smartphone-Based COVID-19 Test That Provides Results in About 10 Minutes

Researchers at the University of Arizona are developing a COVID-19 testing method that uses a smartphone microscope to analyze saliva samples and provide results in about 10 minutes.

The UArizona research team, led by biomedical engineering professor Jeong-Yeol Yoon, aims to combine the speed of existing nasal swab antigen testing with the high precision of nasal swab PCR or chain reaction testing by polymerase. Researchers are adapting an inexpensive method they originally created to detect norovirus – the microbe famous for spreading on cruise ships – using a smartphone microscope.

They plan to use the method in conjunction with a saline gargle test developed by Michael Worobey, head of the Department of Ecology and Evolutionary Biology at Arizona and associate director of the BIO5 Institute at the University of Arizona.

The team’s latest research using water samples – done in collaboration with Kelly A. Reynolds, chair of the Arizona Department of Community, Environment, and Policy Mel and Enid Zuckerman College of Public Health – is published today in Nature’s Protocols.

“We described it so that other scientists could basically repeat what we did and create a norovirus detection device,” said Lane Breshears, a doctoral student in biomedical engineering in Yoon’s lab. “Our goal is that if you want to adapt it for something else, like we adapted it for COVID-19, you have all the ingredients you need to create your own device.”

Yoon – a member of the BIO5 Institute who is also a professor of biosystems engineering, animal and comparative biomedical sciences, chemistry and biochemistry – works with a large group of undergraduate and graduate students to develop the method COVID-19 detection device on smartphone.

“I have a few friends who had COVID-19 who were very frustrated because their PCR results took six or seven days or they received false negatives from rapid antigen tests. But when they got the final PCR tests, they found out they had been sick, as they had suspected, ”said Katie Sosnowski, a doctoral student in biomedical engineering who works in Yoon’s lab. “It’s really cool to work on a detection platform that can get fast and accurate results.”

Cheaper and simpler detection

Traditional methods of detecting noroviruses or other pathogens are often expensive, involve a wide range of laboratory equipment, or require scientific expertise. The smartphone-based norovirus test developed at UArizona consists of a smartphone, a simple microscope, and a piece of microfluidic paper – waxed paper that guides the liquid sample through specific channels. It’s smaller and cheaper than the other tests, with components costing around $ 45.

The basis of the technology, described in a 2019 article published in the journal ACS Omega, is relatively simple. Users introduce antibodies with fluorescent beads into a potentially contaminated water sample. If enough pathogen particles are present in the sample, more than one antibody binds to each pathogen particle. Under a microscope, pathogenic particles appear as small clusters of fluorescent beads, which the user can then count. The process – adding beads to the sample, dipping a piece of paper in the sample, then taking a smartphone photo of it under a microscope and counting the beads – takes around 10 to 15 minutes. It’s so simple that Yoon says a non-scientist could learn how to do it by watching a short video.

The version of the technology described in the Nature’s Protocols the paper makes other improvements, such as creating a 3-D printed housing for the microscope attachment and the microfluidic paper chip. The article also presents a method called adaptive thresholding. Previously, researchers set a fixed value for how much of the pathogen was a hazard, which limited levels of precision. The new version uses artificial intelligence to set the danger threshold and take into account environmental differences, such as the type of smartphone and the quality of the paper.

Impact on campus

The researchers plan to partner with testing facilities at the University of Arizona to refine their method to adapt it to detecting COVID-19. While awaiting approval from the university’s institutional review board, students who are already tested on campus by other methods will have the option of providing written consent to have their sample also analyzed through the testing device. smartphone-based. Ultimately, the researchers plan to distribute the device to campus hubs so that the average person, like a resident assistant in a dorm, can test saliva samples from groups of people.

“The adaptation of a method designed to detect norovirus – another highly contagious pathogen – is an outstanding example of our researchers pivoting in the face of the pandemic,” said University of Arizona President Robert C Robbins. “This promising technology could allow us to provide fast, accurate and affordable testing frequently and easily to the campus community. We hope to make it a regular part of our ‘Test, Trace, Process’ strategy and have more impact. wide to lessen the spread of disease. “

Yoon and his team are also working on another idea, based on a 2018 article they published in Chemistry – A European Journal, which is even simpler but leaves a little more room for error. This is the same technology, but instead of a smartphone microscope and a specially designed case, users would only have to download a smartphone app and use a microfluidic chip stamped with a QR code. .

“Unlike the fluorescence microscope technique, where you place the chip in the correct position, you just need to take a snapshot of the chip,” said Pat Akarapipad, master’s student in biomedical engineering. “No matter the angle or distance from which the photo is taken, the smartphone app can use the AI ​​and QR code to account for the deviations and perform the calculations accordingly.”

The method requires no training, so if perfected, it could potentially allow students to retrieve microfluidic chips on a campus and test their own samples. The team is also working with other members of the COVID testing group. -19 from the university, including Deepta Bhattacharya, associate professor in the Department of Immunobiology.