The global COVID-19 crisis has prompted companies across all industries to shift focus to adapt systems and help fight the pandemic. Companies like GM and Ford have shifted from automobiles to manufacturing ventilators; apparel companies are now producing personal protective equipment such as masks and hospital gowns; and many other companies are using their own industry knowledge and resources to step up and do their part.

Companies have been shifting operations to address different challenges brought on by SARS-CoV-2, including the manufacturing of tests and the processes around detecting the virus. For example, 3-D printing companies like Stratasys and Origin, who normally manufacture automotive and consumer products, have teamed up, and committed to 3-D print more than one million swabs crucial to the testing process, per week in order to catch up with demand.

Other companies, like XpresSpa Group, are addressing test sites. XpresSpa Group operates spa facilities in airports across the United States, but, has quickly pivoted to launch XpresTest Inc., which will convert some of the company’s 46 locations across 23 airports into testing sites for SARs-CoV-2. Currently, the company is in talks with major airports around the United States, including JFK International Airport, Hartsfield-Jackson Atlanta International Airport and Chicago O’Hare International Airport to pilot COVID-19 screening for airline employees, including TSA and U.S. Customs Officers.

My company is focused on diamond and nanocarbon technologies. In our effort to pivot, we are leveraging our access to and existing partnerships with labs to develop more efficient testing devices for SARS-CoV-2. Typically, we’ve pioneered diamond solutions for both optical and electronics applications, addressing critical issues limiting performance across key industries such as aerospace, defense and consumer electronics. Due to our in-depth understanding of semiconductor materials, we quickly understood that our nanocarbon material (first developed to act as a protective coating for optical sensor/detector systems in Army aviation) can address the sensitivity, speed, cost and manufacturing scalability associated with presently available SAR-CoV-2 testing devices.

With the current testing methods for SARS-CoV-2, it can take 5–15 minutes for patients to be diagnosed. However, there is already technology—biosensing field effect transistor (Bio-FET) systems—which can provide diagnostics in seconds. As of right now, Bio-FET devices are already proven to be effective in the detection of viruses like SARS, Ebola and Rotavirus.^1–3 One of the reasons Bio-FET devices are not already being used in SARS-Cov2 testing is because they require advanced nanocarbon materials, and, up until recent breakthroughs in the technology, those materials were expensive and difficult to produce. Since we have been able to address advanced nanocarbon materials, these Bio-FET systems are an attractive next-generation device that will be the key to virus detection in the near future.

How the Bio-FET Test Works

Today, biosensor systems are typically made with silicon semiconductor materials, which leads to major limitations such as large-scale manufacturability.

Nanocarbon semiconductor materials have superior electronic properties (both conductive and insulating) amphiphilicity, biocompatibility and chemical resistance, making these materials ideal FET biosensor material since these FET systems rely on a semiconductor channel to connect the source and drain terminals. In these Bio-FET systems, the charged bio-molecule is attracted, immobilized and then absorbed in the semiconductor, which produces an electric field that changes the charge carrier density within the device. These nanocarbon materials were previously costly and time-consuming to produce, but now that large quantities can be manufactured at low costs, they can be applied to these crucial Bio-FET testing systems.

By utilizing higher quality nanocarbon material, the Bio-FET devices will avoid limitations that have hindered older generations of the technology, like graphene flaking. When industry-standard graphene is used in these devices, it is susceptible to flaking, which completely destroys the active part of semiconductors because the graphene is so thin—it’s a 2-D material and one atomic layer thick. The material’s thinness enables atoms to pile up on top of one another, or spilt and bond to other materials when spread across a large surface. Nanocarbon materials, however, prevent flaking because carbon-to-carbon is amongst the strongest types of covalent bond. This prevents the graphene from bonding with anything else because it is already attached to its preferential atomic bonding partner, leading to an optimized chip.

Secondly, using nanocarbon materials prevents surface oxidation. Surface oxidation happens when oxygen bonds with the graphene used instead of with the virus, as intended. This is a problem with current Bio-FET devices because the semiconductors used are much smaller than the virus it is detecting. So when the virus sits on top of the graphene, it should be easily detectable because it covers the entire surface of the semiconductor. When the virus can’t sit across the entire semiconductor, the oxygen begins to bond with the graphene. With the advanced nanocarbon materials, this is no longer a problem that occurs.

Using nanocarbon materials enables the ability to manufacture Bio-FET sensors at scale, while also addressing the speed at which test results are provided to patients. However, one company won’t be able to end this fight against the SARS-CoV-2 virus alone. It will take many people and companies to step up and help produce the testing materials, or to pivotiaway from traditional offerings to create testing sites. In order to meet the worldwide need for faster and affordable testing processes, companies will need to continue to shift goals and apply resources to ending this pandemic.

References

1. Pant, M., et.al. (2017). “Detection of Rota Virus with the Help of Nanomaterial Based Field Effect Transistor (BIOFET)”. Biosensors Journal. Vol. 6 No. 2. doi: 10.4172/2090-4967.1000149.
2. Ishikawa, F.N., et al. (May 26, 2009). “Label-Free, Electrical Detection of the SARS Virus N-Protein with Nanowire Biosensors Utilizing Antibody Mimics as Capture Probes. ACS Nano. 3(5): 1219–1224. doi:10.1021/nn900086c
3. Chen, Y., et al. (September 8, 2017). “Field-Effect Transistor Biosensor for Rapid Detection of Ebola Antigen”. Scientific Reports. doi: 10.1038/s41598-017-11387-7.