Single Photosynthetic Molecules with Time Resolution

Until now, single molecule spectroscopy and time-resolved spectroscopy were reporting about two distant worlds. Our recent paper show how to connect the best of the two worlds in one experiment.

By Tomáš Mančal

In our recent publication: Pavel Malý et. al, Proceedings of the National Academy of Sciences U.S.A. 113 (2016) 2934, we have demonstrated a time-resolved single molecule spectroscopy with a resolution of about 100 fs. Such a resolution is routinely obtained in standard bulk time-resolved experiments. The problem with them is: they give an averaged information about billions of molecules. The suspicion is however  that the individual lives of the photosynthetic molecules are even more interesting than this average information allows us to imagine. In our paper, we were able to observe for the first time, how some ultrafast properties of the photosynthetic energy transfer change on individual molecules. We could observe how energy relaxation time (on the order of hundreds of femtoseconds) changes over the time-scale of seconds.

Bringing ultrafast science to single photosynthetic molecules promises to help us learn how flexibility of natural photosynthetic systems allows them to self regulate in reaction to change environment.