By incorporating fluorescent carbon nanotubes into spinach plants, researchers have turned the plants into environmental sensors.

Michael Strano and his colleagues at the Massachusetts Institute of Technology in Cambridge coated carbon nanotubes with a peptide that binds to nitroaromatic compounds, which include explosives. They embedded the nanoparticles into the leaves of spinach plants. When chemical contaminants are absorbed by the roots or leaves, they attach to the nanotubes, causing the nanotubes' fluorescence to decrease by an amount that depends on the level of the compound. A small detector picks up the signal and relays it wirelessly to a smartphone.

Living-plant sensors could be deployed to large, remote areas for chemical monitoring, the authors say.

Nature Mater. (2016)