Scientists are developing a smartphone app that can detect COVID-19 in saliva in about 10 minutes.
The technology pairs a phone with a small microscope that analyzes a sample of saliva for evidence of the virus.
Designed by the University of Arizona, the team’s goal is to combine the speed of an antigen test with the accuracy of a polymerase chain reaction, or PCR, test.
The technology was originally developed as an inexpensive method for identifying norovirus, but has been changed in light of the ongoing pandemic.
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Scientists at the University of Arizona have developed a smartphone app that works with a microscope to test saliva samples for COVID-19. The process only takes about 10 to 15 minutes and the components cost about $ 45
The process, reported in the journal Nature Protocols, consists of a microscope and a sheet coated with wax, is called microfluidic paper, which guides the sample through certain channels.
After placing a saliva sample on the paper, the patient introduces antibodies with fluorescent beads.
If there are enough coronavirus particles, the antibodies bind to each one.
“Under a microscope, the particles of the pathogen appear as small clusters of fluorescent spheres, which the user can count”, explained the researchers.
After placing a saliva sample on a sheet of microfluidic paper, the user introduces antibodies with fluorescent spheres. If enough coronavirus particles are present, the antibodies will bind to each other. The virus particles will look like small clusters of fluorescent spheres, which the user can count
According to the researchers, the whole process – adding granules to the sample, soaking the paper in the sample and then taking a picture of the smartphone under a microscope and counting the bills – takes 10 to 15 minutes.
Katie Sosnowski, a doctoral student in the university’s biomedical engineering department, said it was ‘cool’ to work on a test that offered ‘quick and also accurate results’.
“I have some friends with COVID-19 who were super frustrated because their PCR results took six or seven days or because they were getting false negatives from rapid antigen tests,” she said.
– But when they did the final PCR tests, they found they were sick, as they suspected.
The researchers also developed a 3D printed box for the microscope accessory and the microfluidic paper chip. They also developed a method called ‘adaptive threshold’, which uses AI to explain differences in the type of phone used, the quality of the paper and other factors
The team, led by biomedical engineering professor Jeong-Yeol Yoon, originally reported their work in a 2019 article in ACS Omega magazine.
At that time, they were thinking of quick and easy ways to test norovirus, the highly contagious virus that often spreads on cruise ships, but they believe it could be adapted to identify any number of viral infections.
For the coronavirus kit, the team added a 3D printed box for the microscope accessory and the microfluidic paper chip.
A method called ‘adaptive threshold’ has also been introduced, which uses artificial intelligence to define the danger limit and to take into account differences in the type of telephone used, the quality of the paper and other factors.
“We designed it so that other scientists can basically repeat what we did and create a norovirus detection device,” said Lane Breshears, a doctoral student at Yoon.
‘Our goal is that if you want to adapt it to something else, like we adapted it for COVID-19, that you have all the ingredients that you basically need to make your own device.’
Most methods for detecting COVID-19 or other pathogens are time-consuming, expensive and require medical expertise.
The total cost of components for the University of Arizona test is around $ 45 and is easy enough for a layman to do after watching a brief instructional video.
The technology still has a long way to go before it enters the market, but the researchers hope to obtain permission to test samples from students who are already being tested for COVID-19 on campus using other established methods.
Ultimately, they plan to distribute the device across campus so that an AR could test students in a dorm.
“Adapting a method designed to detect norovirus – another highly contagious pathogen – is an excellent example of our researchers dealing with the pandemic,” said University of Arizona President Robert C. Robbins.
“This promising technology can enable us to provide rapid, accurate and affordable testing to the campus community frequently and easily.”
Yoon’s team also designed the adaptation of the technology so that it didn’t even need a microscope, just an application and a microfludic chip with a special QR code.
This would leave a little more room for error, but it would not require any training and could even be self-administered.
Since the arrival of the new coronavirus, scientists around the world have been working to develop faster, cheaper and more convenient testing methods.
Current tests require a cotton swab to the nose and throat, usually in a clinic, which can be time-consuming and unpleasant.
In May 2020, researchers at the University of Pittsburgh announced that they were working on an application that uses artificial intelligence to analyze sounds coming from someone’s airway and determine whether they matched those of a COVID-19 patient.
Developers are working on smartphone apps that can accurately test COVID-19 while being inexpensive, convenient and painless. If successful, it will quickly increase testing and allow people to avoid meeting in clinics or hospitals
Users would need to use an adapter as a mouthpiece so that the phone’s microphone and speaker can record and transmit acoustic signals from their airways.
The goal is to create a simple, inexpensive system that allows people to take the COVID-19 test in their own homes ‘and quickly and effectively identify people with viral diseases,’ said lead researcher Wei Gao.
‘We hope that this work will also help to identify negative cases caused by other diseases with similar symptoms and therefore help to eliminate unnecessary hospital visits during this pandemic.’
Another team from Switzerland is trying to develop a similar system using cough.
‘It seems clear that a large proportion [of coronavirus patients] you have this kind of dry cough that is different from the flu or allergy, ‘Tomas Teijeiro, chief researcher for the Coughvid project, told the Wall Street Journal.
The makers of another app, PocDoc, say it can be combined with your phone’s camera to analyze a blood sample and provide quick results for a COVID-19 antibody test.
A user pricks his finger, puts a drop of blood on the test slide and takes a picture. The software is designed to detect small changes in color when COVID antibodies are present and provide results in five minutes.
‘COVID-19 has accelerated the need for innovative healthcare technology of all kinds,’ said Steve Roest, CEO of PocDoc.