After coming down with a cold, flu or more recently, coronavirus, have you ever wondered, "Where on earth did I catch this?" The possibilities are endless, after all - if the pandemic has taught us one thing, pretty much everything we touch is disgusting. I'm compulsively reaching for the hand sanitiser as we speak.
Well, next time you're wondering whether it was dinner with dad or a breakfast meeting with the boss that got you crook, just think about this: a new mask developed by Chinese scientists can give you the heads-up if you've been exposed to common respiratory viruses.
As per the peer-reviewed scientific journal Matter, the mask can alert the wearer if they've been exposed to COVID-19 or influenza after just a 10-minute conversation with an infected individual. The sensor attached to the mask responded to as little as 0.3 microlitres of liquid containing viral proteins - about 70 to 560 times less than the volume of liquid produced in one sneeze and much less than the volume produced by coughing or talking.
The highly sensitive mask can alert the wearer via their mobile devices within 10 minutes if targeted pathogens are present in the surrounding air.
"Previous research has shown face mask wearing can reduce the risk of spreading and contracting the disease. So, we wanted to create a mask that can detect the presence of virus in the air and alert the wearer," said Yin Fang, the study's corresponding author and a material scientist at Shanghai Tongji University.
Respiratory pathogens that cause COVID-19 and H1N1 influenza spread through small droplets and aerosols released by infected people when they talk, cough, and sneeze. These virus-containing molecules, especially tiny aerosols, can remain suspended in the air for a long period of time.
Fang and his colleagues tested the mask in an enclosed chamber by spraying the viral surface protein containing trace-level liquid and aerosols on the mask.
The team designed a small sensor with aptamers, a type of synthetic molecule that can identify unique proteins of pathogens like antibodies. Aptamers - short, single-stranded DNA or RNA molecules - can selectively bind to a specific target, including proteins, peptides, carbohydrates, small molecules, toxins, and even live cells.
In their proof-of-concept design, the team modified the multi-channel sensor with three types of aptamers, which can simultaneously recognise surface proteins on coronavirus (SARS-CoV-2), bird flu (H5N1) and swine flu (H1N1).
Once the aptamers bind to the target proteins in the air, the ion-gated transistor that's connected to the mask will amplify the signal and alert the wearers via their phones. An ion-gated transistor is a novel type of device that is highly sensitive, allowing the mask to detect even trace levels of pathogens in the air within 10 minutes.
"Our mask would work really well in spaces with poor ventilation, such as elevators or enclosed rooms, where the risk of getting infected is high," Fang said.
In the future, if a new respiratory virus emerges, the scientists can easily update the sensor for detecting the novel pathogens, he added.
Next, the team is hoping to shorten the detection time and further increase the sensitivity of the sensor by optimising the design of the polymers and transistors. They are also working on wearable devices for a variety of health conditions including cancers and cardiovascular diseases.
"Currently, doctors have been relying heavily on their experiences in diagnosing and treating diseases. But with richer data collected by wearable devices, disease diagnosis and treatment can become more precise."
