Researchers from The Massachusetts Institute of Technology embedded spinach leaves with carbon nanotubes — microscopic tubular structures made up of carbon molecules — that turn the plants into living sensors. The nanotubes are attached using a technique called vascular infusion, which involves applying a solution to the underside of the leaf.
“The goal of plant nanobionics is to introduce nanoparticles into the plant to give it non-native functions,” research team leader Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT, said in a press release.
The carbon nanotubes enable the plants to sense chemical compounds called nitroaromatics, which are used in explosives like landmines. When a nitroaromatic compound is present in groundwater that is absorbed by the plant, the nanotubes embedded in the spinach leaves release a fluorescent signal. The signal can be picked up by an infrared camera. A small computer device attached to the camera can even relay the results to a user’s smartphone.