MIT (Massachusetts Institute of Technology) researchers have done it again with another breakthrough experiment that could change the face of public security and make us do a double take when we pass our mother’s potted plant. A team of engineers have created a bionic plant that is able to detect explosives. Even more impressive, the plant can send a warning signal to a specified user and it’s able to do all of this without a single wire. Gone are the days of relying on dogs, rats or even dolphins to detect bombs - we can now turn to the vegetable aisle of our local grocery store.
How are plants doing this?
The science behind the bionic bomb-detecting plant all boils down to tiny cylinders of carbon that are placed on the plant. These carbon cylinders are able to detect specific chemical compounds. So the plants are able to “sniff out” bombs in six steps:
1.) Plants naturally absorb and monitor the air and water around them
2.) Carbon cylinders on the plant will register when the designated chemical compound has entered the plant’s air or water environment. The designated compound will hit the cylinders and bind with a polymer around the tubes.
3.) The carbon cylinders will then emit a fluorescent signal, a change in their standard radiation.
4.) This signal is detected by an infrared camera; only an infrared camera is able to notice the radiation change emitted by the plant
5.) This camera is connected to a computer
6.) And the computer, upon receiving notice of the detection, will email the user
What can the plants detect?
The team at MIT designed their carbon cylinders, or nanotubes, to be able to be tailored to detect any specific dangerous compound. They are able to detect nitroaromatics, a common chemical compound found in explosives. The nanotubes can also detect nitric oxide, a compound released through combustion, and hydrogen peroxide, released in TNT and sarin gas.
The experiment at MIT
To test their new bionic plant in the labs at MIT, the team decided to go with a spinach plant. They painted the leaves of the spinach plant with a solution that contained tiny sensors. The leaves then absorbed this solution and the nanotubes were successfully in place. They poured nitroaromatic contaminants around the roots of the plant and waited for their sensors to go off. Ten minutes later, the nanotubes began to emit an infrared light signal. The infrared camera in place picked up this signal and sent it to the computer. The experiment in plant nanobionics was officially deemed a success!
The team explained that their experiment could have been done using any type of plant and a regular computer or cellphone in place of their infrared camera and computer. At the time of the experiment, the infrared signal emitting from the plant could be detected by a camera up to one meter away. However, the team is hoping to increase that distance in future experiments to make their bionic plant more viable for use outside of the lab.
The team would also be wise to look into ways to reduce the time it takes for the plants to detect the dangerous chemical compound. In their experiment, the sensors on the spinach leaves did not detect the nitroaromatics until ten minutes after the roots of the plant had been doused in nitroaromatic contaminants. While most current forms of bomb detection can work in much less time, the appeal of using plants is obvious when we consider the risk of human or animal life needed with current detection methods.
The bionic bomb-detecting study at MIT was led by Min Hao Wong, an MIT graduate student, and Juan Pablo Giraldo, an assistant professor at the University of California Riverside who previously did postdoc work at MIT. They published their findings in scientific journal Nature Materials at the end of October. The two believe that their study is opening the door for future ways we can use plants for infrared communication and monitoring.
Why are we using plants?
Michael Strano, a chemical engineer at MIT and part of the team behind the bomb-detecting plant, explains that plants are actually natural analytical chemists. Because plants are unable to move to find food or avoid threats, they have to become very good at monitoring their environment and relying on the resources available to them. They are the best groundwater sensors in the world - better than any machine a human could build.
Strano believes this breakthrough with the bionic plant is helping to bridge the gap between plant and human communication. Plants are savvy sensors; they know when a drought is coming way ahead of human-made sensory systems. Strano explains that plants house a wealth of information in their chemical signaling pathways that experiments like MIT’s are helping us to tap into.