Nature still has many secrets from us, despite our ongoing efforts to discover them since our species first learned how to do so. Among these secrets is how photosynthesis works as well as it does, and especially the protein Photosystem-I (PS1). This protein can achieve almost perfect conversion of light to electricity, which is why many are trying to find ways to use it. Now researchers at Technische Universitaet Muenchen and Tel Aviv University have successfully measured the electrical output of a single molecule of PS1, when exposed to light.
The reason to investigate a single molecule is to determine if it can be used in nanotechnology as a power source, but that size also made the investigation difficult. How do you connect leads to a single molecule to measure the electric current produced when you shine light on that molecule? What the researchers did was combine the light source and electrical contact into a single device. The light was guided through a gold-covered glass tip to the molecule, and the conducting tip allowed the researchers to make their measurements.
Finding that even a single molecule of this protein is able to produce a current is very useful as it means PS1 is a viable option for optoelectrical devices at the molecular scale. Hopefully this study will also lead to a better understanding of the protein and eventually a means to use it on the macroscale.