MIT engineers have developed nanobionic spinach plants that can detect buried landmines and hidden explosives.
The researchers were able to do this by embedding the leaves of the spinach with carbon nanotubes transforming them into sensors that can detect explosives and wirelessly transmit the information to a handheld device.
MIT chemical engineering professor Michael Strano said that the approach called "plant nanobionics" aims to introduce nanoparticles into the plant so it can have non-native functions.
For the research, which was described in the journal Nature Materials, Strano and colleagues designed spinach and its nanotubes to react to nitroaromatics found in landmines that leech into the soil surrounding the buried explosives.
Once the roots and vascular system of the plant sucks up the water laced with nitroaromatics, the nanotubes produce a fluorescent light that can be detected using an infrared camera.
"This is a novel demonstration of how we have overcome the plant/human communication barrier," said Strano, who sees potential in harnessing plant power to warn humans of pollutants and environmental conditions such as drought.
Strano described plants as good analytical chemists with extensive root network in the soil that constantly sample groundwater. Plants also have a means to self power the transportation of water up into the leaves.
Although the researchers used spinach, they said that use of basic nanobionic technique is not limited to this plant. It can also be used in almost any plant and just in the case of spinach, the signals can be detected using a smartphone with the right camera.
"These results demonstrate the ability of living, wild-type plants to function as chemical monitors of groundwater and communication devices to external electronics at standoff distances," the researchers wrote in their study.
Bogdan Dragnea, a nanotechnology specialist from Indiana University who was not involved in the study, said that the work is a step towards better monitoring of soil contamination albeit he noted of potential downsides of using the technology.
"A potential caveat is related to possible clearance, and/or biofouling of the transducer by the plant, and the possibility of false positives, but presumably such issues will be addressed further along the road," Dragnea said.
Plants offer scientists hints on how to come up with new technologies beneficial to humans. The researchers said that they hope to improve the number of sensors that can be used in plants so a variety of chemicals in both air and groundwater can also be detected.