Scientists boost photosynthesis in leaves with nanotubes

Scientists at MIT have succeeded in artificially enhancing a plant’s photosynthesis function with the use of carbon nanotubes. As a result of the intervention, the chloroplasts in a plant capture thirty percent more energy from sunlight.

The findings of the researchers at MIT have been published on the university’s website and in an article for the scientific journal Nature Materials. Photosynthesis is the process that takes place in the leaves of plants, in which, among other things, the energy from light is converted into nutrients such as sugars. The carbon nanotubes allow plants to absorb a wider spectrum of light; more energy becomes available to release electrons.

Where a plant normally absorbs a maximum of about ten percent of the energy in sunlight, this increased by thirty percent in the experiment and with isolated chloroplasts even by 49 percent. After introducing the carbon nanotubes into the chlorophyll grains of plants, it was possible to measure more electrons flowing through the membranes of the chloroplasts, indicating more photosynthesis. It is not yet clear how much influence the researchers’ interventions have on the eventual production of glucose in the plants: the researchers have not yet focused on that second step of increasing glucose production. The research could lead to efficient solar cells based on chlorophyll.

MIT researchers apply the carbon nanotubes to the Arabidopsis thaliana plant

In addition, the presence of otherwise modified carbon nanotubes in chloroplasts may allow the plant to act as a chemical sensor. The plant indicates with the color of the leaf whether nitric oxide is present on or in the leaf, which offers the possibility to use plants that have been modified with carbon nanotubes as air pollution monitors. Nitric oxide is a substance that is harmful to the human body, which is released during combustion processes in cars and power stations, among other things. However, adjustments can also be made that allow a plant to detect whether explosives or chemical weapons are nearby, according to the researchers.

With a near-infrared microscope it is possible to see how many electrons move through the leaf