Engineers have turned spinach plants into sensors that can detect explosives and then transmit that information to a handheld device.
The development from a team at MIT is said to be one of the first demonstrations of engineering electronic systems into plants, an approach dubbed plant nanobionics.
“The goal of plant nanobionics is to introduce nanoparticles into the plant to give it non-native functions,” said Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the leader of the research team. Strano is the senior author of a paper describing the nanobionic plants in Nature Materials. The paper’s lead author is Min Hao Wong, an MIT graduate student who has started a company called Plantea to further develop this technology.
The plants were designed to detect nitroaromatics, which are often used in landmines and other explosives. When one of these chemicals is present in the groundwater sampled naturally by the plant, carbon nanotubes embedded in the plant leaves emit a fluorescent signal that can be read with an infrared camera. The camera can be attached to a small computer similar to a smartphone, which then sends an email to the user.
Strano’s lab has previously developed carbon nanotubes that can be used as sensors to detect a wide range of molecules, including hydrogen peroxide, TNT, and sarin. When the target molecule binds to a polymer wrapped around the nanotube, it alters the tube’s fluorescence.
In the new study, the researchers embedded sensors for nitroaromatic compounds into the leaves of spinach plants. Using a technique called vascular infusion, which involves applying a solution of nanoparticles to the underside of the leaf, they placed the sensors into a leaf layer known as the mesophyll, which is where most photosynthesis takes place. They also embedded carbon nanotubes that emit a constant fluorescent signal as a reference.
If there are any explosive molecules in the groundwater, it takes about 10 minutes for the plant to draw them up into the leaves, where they encounter the detector. To read the signal, the researchers shine a laser onto the leaf, prompting the nanotubes in the leaf to emit near-infrared fluorescent light. This can be detected with a small infrared camera connected to a Raspberry Pi. The signal could also be detected with a smartphone by removing the infrared filter that most camera phones have, the researchers said.
“This setup could be replaced by a cell phone and the right kind of camera,” Strano said. “It’s just the infrared filter that would stop you from using your cell phone.”
Using this setup, the researchers can pick up a signal from about one metre away from the plant, and they are now working on increasing that distance.
Now we can expect a lot more spinach on airports.
Very clever, but what are the practical uses? To know if there are any mines in a field you would need to go into it to plant the spinach, and then (assuming you survive) wait a few months for this to grow. Having done all that, and assuming the plants indicate the presence of the explosives, you still have no precise location indicated. Sorry, ‘I’m out’.
Assuming that this can be adopted to give reliable results with other plant life then the main issue would be with inserting the Nano tubes. In theory could the tubes not be inserted via drones or other robotics? How beneficial it would be to do this would depend on a number of factors like the root network of the plant and the time it takes to get a reliable result. I can see potential in this not just for bomb detection but for other applications for example in agriculture and maybe even geological surveys.
I agree with you Nick. I can see this technology used for soil monitoring rather than land mines detection.
Hope this will open up further application of plant nanobionics. May be the beginning of a great future !
But I have never liked spinach!
Popeye will be pleased.
Re: Nicks comments. Presumably you could sow the seed on the verges of roads of ex-war zones like Bosnia and scan the verges safely walking on the tarmac. This would therefore have big advantages in pin-pointing a mine / IED rather than lying prone in a blast suit probing away with a rod.
I love this kind of technology! Would love to discuss with the developers to go for the next -commercial-steps!
To date six comments have been posted with only two being positive 33 1/3 %
That is surely a cause for concern with regard to our nations engineering attitude
I agree with Senior Citizen. Engineers, of all people, should embrace research and the development of new techniques and ideas, even if they do not yet offer fully proven and commercially viable solutions to known problems. This is hugely impressive use of technology!
Come on Engineers: a little levity is good for us all? I fully endorse any effort which removes humans from danger: even if its danger that they sowed? [Isn’t there a parable about that from somewhere?] If the EC regulations as to cabbages runs to 60+ pages, getting the right (left?) type of plants working for us must be good. [That’s worth at least a smile -or is that a simile?]