Scientists at Tufts School of Engineering, Medford, Mass., have developed a way to detect bacteria, toxins and dangerous chemicals in the environment using a biopolymer sensor that can be printed like ink on a wide range of materials, including gloves, masks or other garments. Using an enzyme similar to that found in fireflies, the sensor glows when it detects these otherwise invisible threats.
The biopolymer sensor, based on computationally designed proteins and silk fibroin extracted from the cocoons of a silk moth, can also be embedded in films, sponges and filters, or molded like plastic to sample and detect airborne and waterborne dangers, or used to signal infections—even cancer—in our bodies.
The researchers have demonstrated how the sensor emits light within minutes as it detects the SARS-CoV-2 virus that causes COVID, anti-hepatitis B virus antibodies, the food-borne toxin botulinum neurotoxin B, or human epidermal growth factor receptor 2 (HER2), an indicator of the presence of breast cancer.
Currently, the sensors require a quick spray with a non-toxic chemical after being potentially exposed to bacteria, toxins and dangerous chemicals. If the target is present, then the sensor generates light. The intensity of emitted light provides a quantitative measure of the concentration of the target.
“The 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,” said Fiorenzo Omenetto, Frank C. Doble professor of engineering and director of the Tufts Silklab, where the bio-responsive materials were developed. The sensing element is modular, so developers can swap in newly designed proteins to capture specific pathogens or molecules to measure, while the light emitting mechanism remains the same.
The new technology is described in the journal Advanced Materials.