Researchers at the Tufts School of Engineering have come up with a shapeable sensor that could turn masks, gloves, and everyday clothing into sensors for bacteria, toxins, and dangerous chemicals — and which can be applied to a compact drone to detect SARS-CoV-2 viruses in the air as it flies around a room.
"[This] combination of lab-designed proteins and silk is a sensor platform that can be adapted to detect a wide range of chemical and biological agents with a high degree of specificity and sensitivity," says Fiorenzo Omenetto, professor and director of the Tfts Silklab, of the biopolymer material the team has developed. "For example, SARS-CoV-2 and anti-hepatitis B antibodies can be measured at levels that approach at-home assays."
The material is based on a lock-and-key system powered by an enzyme similar to that which gives fireflies their glow. When a target molecule — which can be anything from a virus to a bacteria or harmful chemical — hits the material, the material begins to glow. The more of the molecule it finds, the brighter the glow.
A big advantage to the team's material is its flexibility: the sensor uses a protein derived from silk cocoons, and can be produced using safe water-based methods. During processing, it can be printed directly onto a surface to turn it into a sensor — or integrated into films, sponges, or fabrics, depending on exactly how it should be used.
To prove the concept, the team set about building a few concept designs — including a bra pad that absorbs bodily secretions to detect the levels of HER2 hormone in the wearer, providing an early warning system for possible breast cancer. Another prototype saw the material applied to the surface of a compact drone, which was able to fly around a room and measure the levels of SARS-CoV-2, the virus responsible for COVID-19.
"You could make surgical masks capable of detecting pathogens, package them in boxes, and use them over time just like conventional masks," adds project co-lead Luciana d’Amone of the sensor material, which is shelf-stable at even high temperatures. "We also showed that you can print the sensor inside food packaging to track spoilage and toxins. You can modify so many products that we use every day to include sensing, and store and use them as you normally would."
The team's work has been published in the journal Advanced Materials under closed-access terms.