NEW YORK – A new COVID-19 test that relies on graphene sensors and electric currents to return results in minutes could be on the market as early as Q2 2022.

IdentifySensors Biologics, a Cleveland-based company with technology that was originally intended to detect food spoilage in the supply chain, has developed a biosensor-based SARS-CoV-2 test that can be mass produced inexpensively while returning results with approximately 96 percent sensitivity, according to spokesperson Joe Mosbrook and cofounder and CEO Greg Hummer.

The firm’s technology, called the Check4 platform, was developed at Case Western Reserve University, and IdentifySensors was moving forward with a plan to adapt it for detecting food spoilage when the COVID-19 pandemic hit. As a result, IdentifySensors changed its plan, Mosbrook said. The company had been working with Purdue University to further develop the tech, and when the focus switched to SARS-CoV-2, the partnership continued, he said. Purdue provided the tools to manufacture the test for its clinical studies and helped with the calibration of the biosensors.
The Check4 platform includes a portable reader the size of a smartphone into which a test cartridge is inserted. A saliva sample from an individual is placed into the cartridge, which contains all of the nanosensors to perform the test. Once the cartridge is placed into the reader, the reader interprets the data and sends it to a cloud-based server, where an algorithm determines the result and sends it back to the user.

The test works by detecting for the SARS-CoV-2 virus based on changes to electrical currents indicative of the presence of the virus in the saliva sample.

The firm’s bio-layered electrochemical sensors have electrodes that are coated with printed graphene and cured at specific temperatures and times for optimal electrical conductivity, Hummer said. A single-stranded DNA biomolecule that is complementary to the N1 gene of the SARS-CoV-2 virus is also on the sensor, and to begin the test the baseline electrical current is measured, which takes about two minutes. Once the saliva sample is applied to the cartridge, nine data points are measured and sent to the algorithm, which then determines whether a result is positive, negative, or undetermined. From placing the sample to receiving results, the process takes about five minutes, Hummer said.
A positive test is indicated by an increase in the current from the baseline measurement, while a negative test is indicated by no change or a decrease in the current, he said. An undetermined result is intended to account for “interference that may happen in the future” with chemicals that people have in their saliva, although Hummer said the company tells users not to take their sample within an hour of eating or drinking to bypass that interference. Thus far, the test hasn’t returned an undetermined result, he said.

The interaction between the biomolecule and the graphene of the sensor “is key” to the test’s accuracy, Hummer said. “How that biomolecule stays or rests on the graphene and the extent to which the graphene is oxidized and cured makes all the difference in the world in terms of being able to detect what we’re looking for.” The specifics of those “hows” are proprietary to the company, Hummer added.

Graphene, a nanomaterial derived from plastic, is being used in other SARS-CoV-2 diagnostic tests, partially due to its remarkable conductivity and strength. Researchers from the University of Illinois at Chicago have developed a new chemistry process to detect the SARS-CoV-2 spike protein on the surface of graphene, and an international research group including experts from the University of Regensburg in Germany and Chung-Ang University in South Korea have created a device that uses a laser to fabricate detection electrodes made from graphene.

In unpublished preliminary studies and proof-of-concept work, IdentifySensors has seen 96 percent to 97 percent sensitivity with a limit of detection of 30,000 copies of the virus per milliliter, although the firm is working on making changes to the electrode to get it lower — hopefully down to 2,000 to 3,000 copies per milliliter, Hummer said.

Rupesh Mishra, lead research scientist at IdentifySensors and a postdoctoral research scientist at Purdue University’s Birck Nanotechnology Center, said that so far, the company has validated the test with over 1,000 artificial saliva samples and 250 clinical samples, which came from Indiana University. He added that the company is hoping to test at least 300 clinical samples before launching the platform. The test cartridge can contain up to five nanosensors, which would allow for multiplex tests, Mosbrook said, although such a test is not currently in development.

While the nanosensor technology is proprietary and patented, Mosbrook said the reader itself is made entirely of off-the-shelf parts, so it’s not hard or expensive to manufacture, current supply chain issues notwithstanding. The nanosensors can be manufactured with inkjet printers, and IdentifySensors is having conversations with printing companies that can manufacture the sensors, Hummer added. The firm is also developing an app for smartphones that would receive the data from the cloud and deliver it to users, either as a text or in an email, Hummer said.

The company’s goal is to begin mass producing the Check4 platform in the second quarter of 2022, and it is currently refining its formula to reach that goalpost, Mosbrook said. Once that final formula is finished, a clinical validation study will be conducted and the test will be submitted to the US Food and Drug Administration for Emergency Use Authorization, hopefully in the next two to three months, Hummer added.

He added that since the FDA is seeking COVID-19 tests that don’t require a lot of expertise — in November, the agency released guidance saying it intends to focus its review of EUA requests on at home and point-of-care tests that can be manufactured in high volumes — the Check4 platform is ideal. It requires only that the reader be on a level surface, and the swab used to collect the saliva sample fluoresces red to show that enough has been collected, he said.
IdentifySensors intends to seek EUA for the platform as both a point-of-care device and a direct-to consumer device, he noted. Although the firm originally saw the test being used primarily in retail settings available at the point of purchase, it has changed its aim, with Mosbrook saying that the company sees “more value in selling it en masse” to organizations that need to test a lot of people very quickly.

The company is promoting its test to foreign governments — specifically Brazil, Japan, and Mexico, where it is close to regulatory approval — and the hospitality industry, including cruise ship companies, Mosbrook said. Outside of the US, the test would be distributed by a commercial or government partner, he said.
According to Mosbrook, the retail consumer cost would be $129 for the reusable reader, which can run up to 20,000 tests, and less than $60 for the single-use test cartridge — “still considerably cheaper than PCR,” he noted. However, it is significantly more expensive than many rapid antigen tests available on retailers’ shelves. Mosbrook added that the firm is seeking a variety of revenue streams, including insurer reimbursement for the test.
IdentifySensors also intends to develop tests beyond COVID-19 using its technology, although there are no hard timelines for when those tests will be ready — a new one could possibly come in early 2023, Mosbrook said. Research scientist Mishra agreed, saying that the detection of many pathogens is possible, and the platform could be expanded to diseases such as methicillin-resistant Staphylococcus aureus and influenza, providing decentralized testing for a variety of illnesses.
The use of graphene sensors, and the Check4 test specifically, “isn’t just a COVID-19 thing,” Mosbrook said. “It could hopefully change medical diagnostics.”