New bionic plants may detect explosives

MIT scientists are developing high-tech bionic plants that can sense pollution and detect explosives or chemical weapons.
Researchers want to make plants even more useful by augmenting them with nanomaterials that could enhance their energy production and give them completely new functions, such as monitoring environmental pollutants.
They report boosting plants' ability to capture light energy by 30 per cent by embedding carbon nanotubes in the chloroplast, the plant organelle where photosynthesis takes place.
Using another type of carbon nanotube, they also modified plants to detect the gas nitric oxide.
Michael Strano, leader of the Massachusetts Institute of Technology (MIT) research team and Juan Pablo Giraldo, the paper's lead author, envision turning plants into self-powered, photonic devices such as detectors for explosives or chemical weapons.

The researchers are also working on incorporating electronic devices into plants.

The idea for these 'nanobionic plants' grew out of a project in Strano's lab to build self-repairing solar cells modelled on plant cells.
The researchers wanted to try enhancing the photosynthetic function of chloroplasts isolated from plants, for possible use in solar cells.
They also showed that they could turn plants into chemical sensors by delivering carbon nanotubes that detect the gas nitric oxide, an environmental pollutant produced by combustion.
Strano's lab has previously developed carbon nanotube sensors for many different chemicals, including hydrogen peroxide, the explosive TNT, and the nerve gas sarin.

When the target molecule binds to a polymer wrapped around the nanotube, it alters the tube's fluorescence.
"We could someday use these carbon nanotubes to make sensors that detect in real time, at the single-particle level, free radicals or signalling molecules that are at very low-concentration and difficult to detect," Giraldo said.
The study was published in the journal Nature Materials.