Understanding Microfluidics – The Key to Rapid COVID-19 Testing

Microfluidics technology is an instrumental part of many widely used testing devices, such as those used to detect pregnancy or abnormal blood sugar levels. A microfluidic device processes tiny amounts of liquids that travel through channels thinner than a strand of human hair. Those chambers feature valves that turn on and off.

People use various materials such as paper, gels, and polymers, to make the channels. It’s then necessary to determine the best way to make the liquid move through those chambers. The possible options include using a mechanical pump or relying on wicking, where energy stored within the liquid makes the movement occur.

Microfluidics captured scientists’ interest long before the COVID-19 pandemic. However, this technology is in the spotlight again now due to its role in rapid testing.

Getting COVID-19 test results in a second

Researchers continually look for better, faster COVID-19 testing methods. Even with vaccines widely available in some places, many employers, airlines, and event venues require people to show negative test results.

A recent effort focuses on amplifying the binding signal for a targeted biomarker to create a better test. The researchers’ previous work indicated that biomarker detection could prove crucial for fighting pandemics, diagnosing heart attacks, and more. Now, they’ve used their knowledge to create a sensor system that gives COVID-19 results within a second.

Minghan Xian, an author of a paper about the achievement, explained in a press release, “Our biosensor strip is similar to commercially available glucose test strips in shape, with a small microfluidic channel at the tip to introduce our test fluid. Within the microfluidic channel, a few electrodes are exposed to fluid. One is coated with gold, and COVID-relevant antibodies are attached to the gold surface via a chemical method.”

Getting test results involves connecting a biosensor strip to a circuit board, then sending an electrical test signal through the gold-coated electrode and an auxiliary one. A transistor amplifies the electrical signal and turns it into a number on a screen representing the concentration of viral protein in the test solution.

The researchers said they could change the antibodies on the gold electrode, making this diagnostic solution applicable beyond the current pandemic.

Diagnosing via smartphones

The COVID-19 pandemic created an urgent need to track how and where the virus spread. Such information helped inform public health decisions and let concerned community members know about potential hot spots. For example, one smart thermometer manufacturer added user body temperature data to a publicly available map. That helped spotlight potentially problematic areas, since a fever is a commonly experienced symptom of infection.

COVID-19 experts have long asserted that effective testing and tracing protocols are essential for keeping the virus at bay. Thanks to advancements in microfluidics, it’s not always necessary to have advanced equipment to get test results efficiently.

A microfluidic device designed at Rice University gives the outcome in less than an hour and plugs into standard smartphones. It contains programmed magnetic microbeads that detect the concentration of SARS-CoV-2 nucleocapsid in blood from a quick finger-prick procedure.

The researchers demonstrated their concept with a Google Pixel 2 smartphone with a piece of electronic hardware – called a potentiostat – plugged into the device. They confirmed that this approach allows giving people results at pharmacies or other points of care without first sending the test off to a lab.

Assessing and improving COVID-19 vaccines and treatments

Scientists engage in ongoing efforts to see how different COVID-19 vaccines work in humans and other animals. That’s especially important as more variants emerge that may reduce effectiveness to some degree.

Researchers also investigate ways to give protection without injections. For example, one study involved administering an intranasal vaccine to hamsters. If such efforts also worked in humans, they could be game-changing, especially for people with a severe fear of needles.

Emerging evidence suggests microfluidic technology will play a vital role in accelerating vaccine development in addition to seeing how current vaccine candidates perform. Then, it’s not only relevant to COVID-19 but also to any disease that could be or currently is vaccinated against.

Microfluidics are also being used to develop antibody treatments for people diagnosed with particular strains of COVID-19. A microfluidic platform can be used to screen blood samples for millions of antibody candidates, allowing rapid engineering of a new treatment.

That example shows microfluidics-based approaches don’t just apply when determining whether someone has COVID-19. This technology can also pay off by significantly ramping up the speed of internal company tests as those organizations develop new options for treating the virus in infected individuals.

Microfluidics propel COVID-19 progress

Hard-working researchers have made impressive and life-saving advances regarding the treatment and diagnosis of COVID-19. This overview highlights why microfluidics have proved instrumental in meeting many of those milestones.

People should expect much of the same in the foreseeable future, especially as scientists become even more familiar with microfluidic technology’s potential and the most appropriate use cases.

About the author:

Devin Partida is a MedTech, innovation and BioMed writer based in San Francisco, California. She is also the Editor-in-Chief of the tech and science magazine ReHack.com.