Researchers are working to create accurate rapid COVID-19 tests with lower costs and less waste than existing rapid clinical laboratory tests
University of Pennsylvania (UPenn) researchers have developed a biodegradable rapid COVID-19 test that raises the bar on traditional polymerase chain reaction (PCR) tests, which throughout the COVID-19 pandemic have been the gold standard for SARS-CoV-2 diagnostic testing.
Many clinical laboratory professionals are aware of the significant amount of waste going into landfills from spent COVID-19 rapid PCR tests that use biosensors to produce results. These biosensor systems “use printed circuit boards, or PCBs, the same materials used in computers. PCBs are difficult to recycle and slow to biodegrade, using large amounts of metal, plastic, and non-eco-friendly materials,” according to a Penn Engineering Today blog post.
UPenn’s new test does not use PCBs. Instead, its biosensor uses “bacterial cellulose (BC), an organic compound synthesized from several strains of bacteria,” the blog post noted.
“This new BC test is non-toxic, naturally biodegradable and both inexpensive and scalable to mass production, currently costing less than $4.00 per test to produce. Its cellulose fibers do not require the chemicals used to manufacture paper, and the test is almost entirely biodegradable,” the blog post continued.
The Penn engineers published their findings in the journal Cell Reports Physical Science titled, “A Bacterial Cellulose-Based and Low-Cost Electrochemical Biosensor for Ultrasensitive Detection of SARS-CoV-2.”
“There is a need for biodegradable diagnostic testing,” said Cesar de la Fuente, PhD (above), Presidential Assistant Professor in the Psychiatry Department at the University of Pennsylvania’s Perelman School of Medicine. “We will be continuing to perfect this technology, which could hopefully help many people in the future, while also looking to expand it to other emerging pathogens in anticipation of future pandemics.” Clinical laboratories engaged in SARS-CoV-2 testing during the COVID-19 pandemic can attest to the massive amounts of waste generated by traditional PCR testing. (Photo copyright: University of Pennsylvania.)
Evolution of Improvement for SARS-CoV-2 Diagnostic Assays
Cesar de la Fuente, PhD, is Presidential Assistant Professor in the Psychiatry Department at the Perelman School of Medicine. His lab has been hard at work since the start of the pandemic to improve COVID-19 testing. The recent study was a collaboration between University of Pennsylvania’s de la Fuente Lab and William Reis de Araujo, Professor in Analytical Chemistry at the State University of Campinas (UNICAMP) in São Paulo, Brazil.
De Araujo leads the Portable Chemical Sensors Lab and has been pairing his electrochemistry expertise with de la Fuente’s lab for years, Penn Engineering Today noted.
The team wanted to combine the speed and cost-effectiveness of previous rapid tests with an eco-friendly biodegradable substrate material.
Bacterial cellulose (BC) was a great choice because it “naturally serves as a factory for the production of cellulose, a paper-like substance which can be used as the basis for biosensors,” Penn Engineering Today reported.
Additionally, BC has an excellent track record for a variety of uses, such as regenerative medicine, wound care, and point-of-care (POC) diagnostics, the blog post noted. UPenn’s test offers speed and accuracy without needing costly equipment making it desirable for clinical laboratories preparing to fight the next pandemic.
The test has shown to be capable of “correctly identifying multiple variants in under 10 minutes. This means that the tests won’t require ‘recalibration’ to accurately test for new variants,” Penn Engineering Today added.
Innovation Born from Inspiration
Though rapid tests are essential to help curb the spread of COVID-19, the negatives that come with these tests didn’t sit well with the UPenn team. This spurred them to strive for improvements.
PCR tests “are hampered by waste [metal, plastic, and the aforementioned PCBs]. They require significant time [results can take up to a day or more] as well as specialized equipment and labor, all of which increase costs,” Penn Engineering Today noted.
Additionally, “Sophistication of PCR tests makes them harder to tweak and therefore slower to respond to new variants,” the blog post concluded.
“There’s a tension between these two worlds of innovation and conservation,” de la Fuente told Penn Engineering Today. “When we create new technology, we have a responsibility to think through the consequences for the planet and to find ways to mitigate the environmental impact.”
Need for Biodegradable Diagnostic Tests
“COVID-19 has led to over 6.8 million deaths worldwide and continues to affect millions of people, primarily in low-income countries and communities with low vaccination coverage,” the Cell Reports Physical Science paper noted.
“There is a need for biodegradable diagnostic testing,” de la Fuentes told Penn Engineering Today. “We will be continuing to perfect this technology, which could hopefully help many people in the future, while also looking to expand it to other emerging pathogens in anticipation of future pandemics.”
While UPenn’s test will require clinical trials and FDA approval before it can become available to clinical laboratories and for point-of-care testing, it promises a bright, eco-friendly future for rapid viral testing.
—Kristin Althea O’Connor