The laser light source used in this study was developed in the Physics Department at Imperial College and the technology transferred to RAL. It is capable of producing ultra-short pulses of light of very high intensity which are made up of a broad range of colours
Instant pictures showing how the sun’s energy moves inside plants during photosynthesis have been taken for the first time, according to new research published in Physical Review Letters.
Scientists hope to understand the energy transport process of photosynthesis in more detail in order to harness this process as they search for new energy solutions to replace fossil fuels. Until now, it has been difficult for scientists to explain how photosynthetic molecules are able to transport energy with remarkably high efficiency.
“These new pictures are instantaneous snap-shots of energy being transported between electrons across a protein. Remarkably, the pictures go further in unravelling the complex way the electrons interact. This gives us something akin to a fingerprint for electronic couplings,” says Dr Ian Mercer from the UCD School of Physics, the lead author of the new study, who is a visiting researcher at Imperial College London.
The research was carried out using a bacterial protein, provided by the University of Glasgow, which harvests light in the same way as photosynthetic plant proteins. By illuminating the sample with a combination of high power laser pulses all derived from the same laser, the researchers obtained a map of bright spots on a camera in a tiny fraction of a second. The position of each spot corresponds to a unique angle of light emitted from the sample and this directly relates to how electrons in the protein respond to the laser light and to each other.
The researchers used the Astra laser at the Science and Technology Facilities Council’s Rutherford Appleton Laboratory (RAL). It incorporates state-of-the-art technology developed in the Physics Department at Imperial College London to produce pulses of light with the right properties for this experiment.
With this laser, a map can be captured with a single pulse of laser light meaning that full information can be gathered prior to, or during, a chemical reaction.
“Hopefully one day we will be able to harness the exquisite mechanisms that we learn about from molecules, whose function has been honed by evolution over hundreds of millions of years”, says Dr Mercer. The researchers are currently applying this approach across the molecular biosciences and with electronic devices.
