Glowing 'live' gloves help crime scene investigations

The "active material" is made from a hydrogel filled with programmed bacteria that glow when they react with certain chemicals. (Courtesy of researchers/MIT)

Luminous gloves made of "living material" could one day replace the "CSI"-style blacklights currently used to detect certain substances in crime scene investigations and other scientific applications, according to a new study.

A team of researchers has bioengineered a "biomaterial" that glows when exposed to certain chemicals, according to a new study. In the new study, the researchers describe the biomaterial -- a hydrogel filled with E. coli cells -- and its potential applications. When the cells are exposed to different chemicals, they are genetically reorganized using fluorescence to make them glow.

So far, the researchers have injected the hydrogel into gloves and bandages, but they say the active substance could be used in crime scene investigation, medical diagnostics, pollution monitoring, and more. [Superintelligent Machines: 7 Robot Futures] "KDSPE" "KDSPs" "With this design, one could place different types of bacteria in these devices to indicate toxins in the environment, or skin disease," study co-author Timothy Lu, an associate professor of bioengineering at MIT, said in a statement. We are demonstrating the potential of biomaterials and devices.

While the goal is wearable sensors, researchers have seen the most success testing programmed cells in petri dishes, where the environment can be carefully controlled. Maintaining live cells when they are deployed in a functioning device is a major challenge in the team's research.

To find hosts for his programmed cells, Lu worked with Xuanhe Zhao, an associate professor of civil, environmental, and mechanical engineering at MIT. Zhao and his colleagues worked on different hydrogel formulations, and their latest generation provides a stable environment for this bioengineered bacteria. The hydrogel, which is about 95 percent water, does not break when it is stretched or pulled, and it can absorb oxygen while fusing with a layer of rubber.

One test of the cell-filled hydrogel included a bandage, or "living patch," programmed to respond to rhamnose, a natural sugar found in plants. The researchers also tested a glove whose fingertips glowed when exposed to different chemicals. In both tests, the cells remained stable in the hydrogel and glowed appropriately in the presence of the chemicals.

For future biomaterials, the team also developed a theoretical model to guide the researchers' designs.

"The model helps us design biological devices more efficiently," Zhao said it tells you the thickness of the hydrogel layer you should use, the distance between channels, how to design the channels, and how much bacteria to use.

The MIT team's living material is described in a study published online Feb. 15 in the Proceedings of the National Academy of Sciences.

Original article on Life Sciences.