Plants make life as we know it possible. It all starts with the tiny organelles within a plant's leaves, known as chloroplasts. These chloroplasts—diminished descendants of the first photosynthesizers, cyanobacteria—use incoming sunlight to split water molecules and then knit together the energy-rich carbon and hydrogen compounds found in everything from food to fossil fuels. The leftover “waste” is the oxygen that we and the rest of the animal kingdom depend on to survive and thrive.
But chloroplasts aren't very efficient. They do not absorb green light (which is why most plants appear green) as well as the sun's heat, also known as infrared light. They generally waste a lot more sunlight than they use; photosynthesis maxes out at roughly 10 percent of the incoming sunshine. So why not give flora, and the chloroplasts within their leafy photosynthetic machines, a boost?
That's exactly what a group of chemical engineers and biochemists attempted in a new study, embedding single-walled carbon nanotubes—microscopic tubes thinner than a human hair that can also absorb sunlight and convert it to electron flow—in living chloroplasts. The paper is published in Nature Materials on 16 March. (Scientific American is part of Nature Publishing Group.)