Electrical current from plants
The electrons were intercepted just after excitation
The tiny current was produced by photosynthesis
Plants use photosynthesis to convert light energy to chemical energy, which is stored in the bonds of
sugars they use for food. The process takes place in chloroplasts, the cellular powerhouses that make
sugars and give leaves and algae their green color.
In the chloroplasts, water is split into oxygen, protons and electrons. Sunlight penetrates the chloroplast
and zaps the electrons to a high energy level, and a protein promptly grabs them.
The electrons are passed down a series of proteins, which successively capture more and more of the
electrons' energy to synthesize sugars until all the electron's energy is spent.
In an experiment, researchers intercepted the electrons just after they had been excited by light and
were at their highest energy levels. They placed the gold electrodes in the chloroplasts of algae cells,
and siphoned off the electrons to generate a tiny electrical current.
In the electrifying first, Stanford scientists have plugged in to algae cells and harnessed a tiny electric
They found it at the very source of energy production – photosynthesis, a plant's method of converting
sunlight to chemical energy. It may be a first step toward generating “high efficiency” bioelectricity that
doesn't give off carbon dioxide as a byproduct, the researchers say.
“We believe we are the first to extract electrons out of living plant cells,” said WonHyoung Ryu, the lead
author of the paper published in the March issue of Nano Letters. The Stanford research team
developed a unique, ultra-sharp nano electrode made of gold, specially designed for probing inside cells.
They gently pushed it through the algal cell membranes, which sealed around it, and the cell stayed
alive. From the photosynthesizing cells, the electrode collected electrons that had been energized by
light and the researchers generated a tiny electric current