In the testing phase, a prototype N95 face mask with a sensor built into the breath valve appears to be highly sensitive to virus proteins.
After a 10-minute conversation with an infected person, a face mask with an integrated virus sensor could detect trace levels of the coronavirus.
The mask would then send a signal to the person wearing the face cover a smartphone, letting them decide to either leave an area where coronavirus is visible – or to delete their mask if they felt confident when no virus has been detected.
Even so, the results so far are based on initial studies. As according to Yin Fang of Tongji University in China, the mask has not yet been tested against whole viruses, just the coronavirus’s surface proteins, and the technology is still in development.
Fang’s team developed a face mask that detects outer proteins from three viruses: two flu strains, H5N1 and H1N1, and SARS-CoV-2, the virus that causes covid-19.
Aptamers, short strands of DNA or RNA that can be designed to bind to specific proteins, are employed in the sensor within the mask’s breath valve. Aptamers are smaller and more stable than antibodies, which are used to detect the coronavirus spike protein in lateral flow tests.
So when aptamers bind to their target proteins, the electrical charge of the aptamers changes and an integrated chip in the mask sends a signal to a designated smartphone.
The mask had been tested by putting it in a closed chamber and spraying it with tiny drops of liquid containing the coronavirus spike protein or surface proteins from the two flu viruses, similar to those produced when an infected person coughs or talks. The system could detect as little as 0.1 femtograms (0.0000000000000001 grams) of protein per milliliter of fluid after 10 minutes.
According to Fang, the mask could be useful for people who need to be in indoor spaces with poor ventilation. “It’s a new technique for protecting the people.” As per him, the system could also be updated with aptamers that recognize different pathogens.
Scientists are yet to ascertain how commonly the mask inaccurately emits an alert signal when it comes into direct contact with surface proteins from other viruses.
According to Al Edwards of the University of Reading in the U.k, the idea has potential but must be examined further. “It’s really difficult for things to work in the real world,” he says.
He appears to believe that the principle of using highly sensitive aptamer-based tests could be implemented in other settings, such as placing sensors within ventilation units or hospital wards.
