Turning plants into lamps

A nanobionic light-emitting plant used to illuminate books.

After designing plants that can detect explosives and give out an early warning of an impending water shortage, a research team at Massachusetts Institute of Technology (MIT) in the United States has found a way to create plants that glow.

Chemical engineers led by MIT professor Michael Strano embedded nanoparticles into the leaves of an edible aquatic watercress plant to make them glow, just enough to give off dim light for four hours.

According to Strano, their goal is to make a plant that will function as a desk lamp—a lamp that does not need to be plugged in. The light is ultimately powered by the energy metabolism of the plant itself. The technology could be harnessed to provide low-intensity indoor lighting or transform trees into self-powered street lights, said the scientists, who published the study in the journal Nano Letters recently.

Strano’s laboratory has been doing some pioneering work in the area known as plant nanobionics. Last year, they turned spinach plants into detectors that can detect landmines and other explosives. Last month, another study from Strano’s team reported how ultra tiny sensors can be printed onto leaves so that they can warn of a water shortage, helping farmers find a way to ensure judicious use of water in farming.

To create their glowing plants, the team turned to luciferase, the enzyme that gives fireflies their glow. Luciferase acts on a molecule called luciferin, causing it to emit light. Another molecule called “co-enzyme A” helps the process along by removing a reaction byproduct that can inhibit luciferase activity.

The scientists packaged each of these three components into a different type of nanoparticle carrier. The nanoparticles would help each component get to the right part of the plant. They also prevent the components from reaching concentrations that could be toxic to the plants.

The next logical step for the MIT scientists would be to find how the new technology can help in lighting, which accounts for about 20 per cent of worldwide energy consumption.

Compiled by T.V. Jayan