By Stephanie Kalina-Metzger
Scanning electron micrograph (SEM) of tomato spotted wilt virus trapped in a CNT microfluidic device. False blue color was added manually.
There’s always new, cutting-edge technology in the works at Penn State. One of the more recent developments involves a group of Penn State professors working with scientists on solutions to identify and capture viruses. Virolock is led by President Mauricio Terrones, Ph.D., with co-founders Nestor Perea-Lopez, Ph.D., and Yin-Ting Yeh, Ph.D.
Terrones said that Virolock’s current work centers on growing carbon nanotubes (CNTS) in a lab. This involves passing a hydrocarbon vapor through a tube furnace assisted by a catalyst material that is high enough in temperature to decompose the hydrocarbon. CNTS grow over the catalyst and CNTS grow over the substrate containing a patterned catalyst.
“We’re trying to detect viruses in the air in a crowded room, in restaurants, hospitals, student unions and may be able, at some point, to detect a new, emergent virus almost immediately and take action."
“The idea is to use CNTs to block particles of specific sizes. For example, Covid and flu viruses are around 100-130 nanometers in diameter,” he said.
Out of this work emerged a hand-held device that captures viruses based on size, from samples thought to contain viruses.
After growing the CNTs, Virolock collaborated with scientists to create a diagnostic tool to rapidly trap and identify viruses using a laser beam and a detector, with a technique called Raman Spectroscopy. Raman spectroscopy is a process where viruses are identified by shining a light on a disposable cartridge that collects samples from a patient’s saliva taken with a cotton swab, or a person blowing through a device called a microfluidic cartridge.
Once a sample is collected, a spectrometer measures vibrations that result from shining a light on the collected vibrations. “Each virus has its own signature vibrations,” said Terrones, adding that influenza, for instance, would have a different signature vibration than, say, coronavirus.
"Within two minutes, a person would know if they have a respiratory virus by comparing the result of the spectroscopy test with other results in the database."
“We then use Raman spectroscopy to identify the viruses based on their individual vibration,” said Terrones.
Right now, the most common type of test for coronavirus takes several hours and is uncomfortable. Samples are obtained by sliding a swab into the nose or throat.
“With this new technology, you collect the sample, pass it through the device, shine a laser on the surface of the material and that will give you the fingerprint of the virus. You could detect one virus, or multiple viruses,” said Terrones, adding that every time a sample is collected, it can be stored in a database.
According to Terrones, an identification will take less than two minutes, with an accuracy rate of 70 to 90%, compared to today’s state-of-the-art microbiology techniques.
Terrones explained this technology is cutting-edge partially due to the lack of antibodies needed. “Right now, the tools people use to detect viruses need antibodies. We don’t. Keep in mind that using antibodies relegates us to identifying just one virus. With our technique, we can trap and study them all,” said Perea-Lopez.
Terrones, remarking on coronavirus, stresses the importance of rapid and accurate detection.
“Raman spectroscopy has not only the potential to help with coronavirus, but also other illnesses, like the flu, to halt disease spread. It has the potential to save hundreds of thousands of lives a year,” he said, adding that it differs from both immune and molecular-based methods, which require prior knowledge of the strains. The Raman technique, on the other hand, can detect several different viruses at once, making the technique both novel and viable.
The Virolock team is reaching out to the federal government to demonstrate that its technology works to detect Coivd-19, so that the team can eventually build prototypes that can be scaled up for mass production and field deployment.
“We see this technology eventually becoming available to anyone visiting their family doctor. Within two minutes, a person would know if they have a respiratory virus by comparing the result of the spectroscopy test with other results in the database,” said Terrones, adding that the technology could one day be installed in hospitals, commercial aircrafts and airports.
Otherwise, the team at Virolock is working on ways to halt future pandemics, according to Terrones.
“We’re trying to detect viruses in the air in a crowded room, in restaurants, hospitals, student unions and may be able, at some point, to detect a new, emergent virus almost immediately and take action,” Terrones said.
“Raman spectroscopy has not only the potential to help with coronavirus, but also other illnesses, like the flu, to halt disease spread. It has the potential to save hundreds of thousands of lives a year."
The team also foresees establishing a center for virus surveillance to address the issue of virus trajectories, expanding that to animals as well.
“I see this technology lending itself to farming, since farm animals get diseases like avian flu and crops are even affected by viruses,” said Perea-Lopez.
“We even learned that deer were affected by COVID. That means it was circulating among the deer and can mutate in a different way. If you can monitor all these things in real time, you can make a tremendous difference, which is our goal and we are proud that Penn State is leading the way when it comes to virus detection,” added Terrones.