Living sensor lights up upon pathogen exposure

February 21, 2017 // By Julien Happich
A multidisciplinary team of researchers from MIT combined the special properties of hydrogels (consisting of up to 95 percent water) with genetically modified living cells programmed to light up in the presence of certain chemicals to create a new type of living sensors.

The researchers fabricated various wearable sensors from cell-infused hydrogels, including a rubber glove with fingertips that glow after touching a chemically contaminated surface, and bandages that light up when pressed against chemicals on a person’s skin.

Their paper published this week in the Proceedings of the National Academy of Sciences, demonstrates the new material’s potential for sensing chemicals, both in the environment and in the human body.

According to Xuanhe Zhao, the Robert N. Noyce Career Development associate professor of mechanical engineering at MIT, such hybrid "living materials" could be adapted to sense a variety chemicals and contaminants, for uses ranging from crime scene investigation and forensic science, to pollution monitoring and medical diagnostics. While the hydrogel efficiently confines the living cells in a moist and nutrient-rich environment, it is tough and compliant enough to be co-designed with other flexible rubbery materials to design versatile biochemical sensors.

In the past, scientists could only maintain the reactive cells alive in the carefully controlled environment of a Petri dish, making it difficult to exploit their fluorescent properties in synthetic materials. Here the researchers first fabricated layers of hydrogel and patterned narrow channels within the layers using 3-D printing and micro-moulding techniques.