New biosensors quickly detect coronavirus proteins and antibodies

Scientists have created a new way to detect the proteins that make up the pandemic coronavirus, as well as antibodies against it. They have designed protein-based biosensors that glow when mixed with virus components or specific COVID-19 antibodies. This breakthrough could enable faster and wider distribution in the near future. The research appears in Nature.

To diagnose coronavirus infections today, most medical laboratories rely on a technique called RT-PCR, which amplifies genetic material of the virus so that it can be seen. This technique requires specialized personnel and equipment. It also consumes laboratory supplies that are currently in great demand worldwide. The supply chain shortages delayed the COVID-19 test results in the United States and beyond.

In an effort to detect coronavirus directly in patient samples without the need for genetic enhancement, a team of researchers led by David Baker, professor of biochemistry and director of the Institute of Protein Design at UW Medicine, used computers to develop new biosensors design. These protein-based devices recognize specific molecules on the surface of the virus, bind to them and then emit light through a biochemical reaction.

Antibody testing can show if anyone has had COVID-19 in the past. It is used to detect the spread of the pandemic, but it also requires complicated laboratory supplies and equipment.

The same team of UW researchers also created biosensors that glow when mixed with COVID-19 antibodies. They showed that these sensors do not respond to other antibodies that may also be in the blood, including those targeted by other viruses. This sensitivity is important to avoid false-positive test results.

“We have shown in the laboratory that these new sensors can easily detect viral proteins or antibodies in simulated nasal fluid or donated serum,” Baker said. ‘Our next goal is to ensure that it can be used reliably in a diagnostic environment. This work illustrates the power of de novo protein design to create molecular devices from scratch with new and useful features. ‘

In addition to COVID-19, the team also showed that similar biosensors can be designed to detect medically relevant human proteins, such as Her2 (a biomarker and therapeutic target for some types of breast cancer) and Bcl-2 (which have clinical significance in lymphoma and some other cancers), as well as a bacterial toxin and antibodies directed against Hepatitis B virus.