Imagine that instead of lighting a lamp when it gets dark, you could read exclusively with the light of a bright plant. This is what a team of engineers from the Massachusetts Institute of Technology (MIT) has achieved: take the first step to make this vision a reality.
To create these plants that glow in the dark, as if immersed in the universe of James Cameron’s Avatar, the scientists incorporated specialized nanoparticles in the leaves of a watercress plant, inducing the plants to emit dim light for almost four hours.
Experts believe that, with greater optimization, these plants will one day be bright enough to illuminate a work space.
“The idea is to make a plant that works like a desk lamp, a lamp that does not have to be plugged in. The light is finally driven by the energy metabolism of the plant,” says Michael Strano, leader of the study published by Nano Letters magazine..
This technology could also be used to provide low-intensity interior lighting, or to transform trees into autonomous lampposts, the authors write.
What they do is provide the plants with novel features introducing different types of nanoparticles. The objective of the team is to design plants to take care of many of the functions now performed by electrical devices.
Lighting, which represents approximately 20% of the world’s energy consumption, seems to be the next logical goal. “Plants can self-repair, have their own energy and are already adapted to the external environment, We believe that this is an idea that has reached the moment, It is a perfect problem for the nanobionics of plants,” says Strano.
How did they do it?
To create the bright plants, the MIT team turned to luciferase, the enzyme that gives shine to precious fireflies. Luciferase acts on a molecule called luciferin, which allows it to emit light. Another molecule called coenzyme A helps the process, eliminating a by-product of the reaction that can inhibit the activity of luciferase.
The MIT team packaged each of these three components into a different type of nanoparticle carrier (classified by the FDA as “generally considered safe”), which helps each component reach the correct part of the plant. They also prevent the components from reaching concentrations that could be toxic to plants.
The researchers used silica nanoparticles about 10 nanometers in diameter to transport luciferase, and used slightly larger particles of the PLGA and chitosan polymers to transport luciferin and coenzyme A, respectively.
To obtain the particles in the leaves of the plants, they first suspended the particles in a solution. The plants were submerged in this solution and then exposed to high pressure, allowing the particles to enter the leaves through small pores called stomata.
The first experiments produced plants that shone for about 45 minutes, and have since improved up to 3.5 hours. The light generated by a watercress plant ( Nasturtium officinale ) of 10 centimeters is currently about one thousandth of the amount needed to read, but researchers believe they can increase the light emitted, as well as the duration of the light, by further optimizing the concentration and release of the components.
For future versions of this technology, researchers hope to develop a way to paint or spray nanoparticles on the leaves of plants, which could allow the transformation of trees and other large plants into light sources.