Low Cost, Saliva-Based COVID-19 Test Inspired by Glucose Test Strips for Diabetes Detects SARS-CoV-2 in 15 Minutes

Researchers are developing a rapid, low cost and mass manufacturable saliva-based biosensor test for COVID-19 inspired by the glucose test strips used to check blood sugar levels in people with diabetes.

The team from the University of Strathclyde (Glasgow, Scotland) claims that the test could eventually be mass manufactured for as little as 20 pence per test. It is designed for rapid in the field use, similar to a lateral flow test, to allow people in community settings to determine their COVID-19 status.

When a person is self-testing, they would put saliva directly onto the test strip where the measurement is run by the instrument and the result produced on a display, avoiding the discomfort associated with nasopharyngeal swabs. Compared to other diagnostic tests, glucose blood tests can already be manufactured at scale, with test strips and readers CE marked with regulatory approval for use in the management of diabetes. This means the route to producing a COVID-19 test based on the technology can be much quicker.

The team of researchers has applied a special chemical treatment to the sensor surface to produce the test, which uses the ACE2 enzyme - the receptor that coronavirus uses to bind on to cells - meaning clinically relevant detection levels of the virus can be achieved. The experimental sensor was initially tested with inactivated virus samples at different concentrations, ranging from low to high, alongside negative samples from a commercially available molecular diagnostics standards kit. Hospital laboratory tests were then carried out on real patient samples and most recent set of experiments showed detection was possible in 15 minutes.

The team has patented the experimental technology and will use clinical samples to translate this proof of concept work into a working product. The aim is to develop the test into a CE marked commercial product for real world use. The first version of the test for emergency use is expected to be ready in 12 months and a fully CE marked test is likely to be on the market in 18-24 months.

“The test would provide a scalable route to sensitive, specific, rapid and low-cost testing for COVID-19, but in addition could serve as a low cost tool to rapidly diagnose other respiratory viruses and determine whether someone has COVID-19, flu or rhinovirus,” said lead investigator, Dr. Damion Corrigan from the department of Biomedical Engineering at Strathclyde. “This means it could enable screening of workers, at very low cost, for example in their place of work, identifying and isolating those with the disease and enabling those recovered to go back to work. Initially, we will demonstrate this with COVID-19 and then commercialize the test so that we can work on using the underlying patent to produce new sensor technologies for other respiratory viruses and infectious diseases.”

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The University of Strathclyde