Detecting explosives with spinach: Popeye would be proud

With the world in turmoil nowadays and terrorists planting explosives everywhere, MIT professor Michael Strano has taken a very unusual and unexpected approach as one possible solution to this problem. Strano’s research in nanobionics has the goal of introducing nanoparticles into plants with the purpose of giving them functionality that they would not normally possess.

Image courtesy of MIT News

Image courtesy of MIT News

Spinach leaves were embedded with carbon nanotubes which gave them the uncanny ability to detect explosives and believe-it-or-not the ability to send information wirelessly to a handheld smart-phone type of device. See the following video courtesy of MIT News:

Landmines and other various explosive devices can contain chemical compounds called nitroaromatics. When a plant such as spinach absorbs ground water that contains that chemical, the embedded carbon nanotubes in the leaves will emit a fluorescent signal which an infrared camera can detect. That camera can be integrated with a smart-phone-like transmitting device to send an e-mail wirelessly to any destination to which it is programmed.

Other possible applications to benefit planet Earth are the ability to warn farmers or other agencies of pollutant compounds in the soil or to warn of the beginnings of a drought condition that can be remedied before it can destroy crops.

Professor Strano’s prior research in this area has enabled plants to detect hydrogen peroxide, TNT and the Sarin nerve gas. The nanotube’s fluorescence is altered by these compounds when the target molecule binds itself to a polymer in which the nanotube is wrapped.

The research team first embeds some carbon nanotubes, which emit a constant fluorescence, as a reference. The system will compare that reference fluorescence signal with the nitroaromatic compound of choice to determine if the explosive sensor has detected an explosive compound. It only takes about 10 minutes for the planet to draw the groundwater containing an explosive compound into the leaves which contain the detector.

The detector is fabricated by applying a solution of nanoparticles to the underside of some leaves in a layer of the leaf known as the mesophyll where photosynthesis happens. In order to read that signal, a laser is shined onto the leaf area which will prompt the nanotubes in the leaf to emit a near-infrared fluorescent light.

A tiny infrared camera is connected to a Raspberry Pi. The camera in a smartphone can be used instead if the infrared filter is removed (Most smartphone cameras have this filter). Right now the design is capable of transmitting as far as one meter, but the design is being modified for greater distance capability.

Imagine what other amazing functions can be accomplished by using plants and electronic materials? Can you think of any?

1 comment on “Detecting explosives with spinach: Popeye would be proud

  1. RadioGraybeard
    November 10, 2016

    “Detecting Explosives with Spinach” has got to be the headline of the day.  As for what else might be detected with it, that seems to be a matter of imagination.  If a compound can be derived that will make the carbon nanotubes flouresce, and work in their process, it seems they could detect anything.


    My question is how the researchers get the carbon nanotubes embedded in the leaves.  Do they have to be manually inserted?  One can imagine some sort of spinach surgery, but are they injected with needles?  It would seem the nanotubes would be too big to get across the root hairs and be absorbed with the water.  Can they be just sprinkled on the plants?



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