Portable, reusable COVID-19 sensor tests in 60 seconds

Technology News | May 8, 2020

By Rich Pell

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About the size of a quarter, the sensor, says electrical and computer engineering professor Massood Tabib-Azar, works with a cellphone and can detect COVID-19 in just 60 seconds.

“It can be made to be a standalone device, but it can also be connected to a cellphone,” says Tabib-Azar. “Once you have it connected either wirelessly or directly, you can use the cellphone software and processor to give a warning if you have the virus.”

Based on a sensor Tabib-Azar first began developing for the NSF about a year ago to detect the Zika virus, the sensor would use just a drop of saliva and can produce results in a minute. The sensor would use single-strand DNA – called aptamers – in the sensor that would attach to the proteins in the COVID-19 virus molecule if it is present, with an electrical resistance being measured in the device to signal a positive result.

To test for the virus, a user would plug the small sensor into a cellphone’s power jack and launch an app made for the device. The user would then place a drop of saliva on the sensor, and the results would appear on the phone.

The sensor is designed to also test for the virus on surfaces by brushing a swab on the surface and then on the sensor. And, says Tabib-Azar, it might be able to detect the presence of COVID-19 in floating microscopic particles in the air in enclosed spaces such as an elevator. (While the virus is currently considered not airborne, studies are being conducted to determine if minute particles of the virus can hang in floating droplets in the air.)

The sensor would include an array of tiny devices inside it, each with a DNA strand that looks for a different protein. A specific combination of proteins would be unique to just COVID-19.

“By increasing the number of devices and single-strand DNA,” says Tabib-Azar, “we can increase the sensor’s accuracy and reduce the false positives and false negatives.”

The sensor is designed to be reusable by being able to destroy the previous sample on it by producing a small electrical current that could heat up and remove or disintegrate the virus. According to Tabib-Azar, the entire process would use little battery power from the cellphone.

Another possible method for using the sensor, says Tabib-Azar, would involve putting the saliva sample on disposable sheets that are placed on top of the sensor like a Sticky Note. This would decrease cross contamination on the sensor and eliminate the need to heat up and destroy the sample afterward.

The device can also be designed to upload the results to a central server that maps out positive results in an area, giving researchers a clearer and more accurate picture of where hotspots are with big outbreaks of the virus. Because the technology – and a prototype – has already been developed to detect the Zika virus, says Tabib-Azar, he expects to be able to have a prototype of the new COVID-19 sensor for clinical trials in two to three months.