Chlorophyll in plants, during photosynthesis, absorbs photons (energy) from the sun. This energy is transferred to other chlorophyll molecules organized by protein scaffolds and funneled into the next stage of photosynthesis.
The early light-harvesting stages of photosynthesis involve repeated excitation of pigments. MIT Associate Professor Gabriela Schlau-Cohen used ultrafast spectroscopy to capture these highly dynamic processes.
What is Ultrafast spectroscopy?
Ultrafast spectroscopy is a technique that uses extremely short laser pulses to study events that happen on timescales of femtoseconds to nanoseconds.
Through this, Schlau-Cohen has discovered how photosynthesis is regulated under different light conditions, and how plants protect themselves from damage by dissipating excess sunlight.
“We are really interested in understanding the dynamics of electronically excited states, in photosynthesis and other systems. We’re studying how energy can migrate through molecular systems and what controls the nature of that migration and its efficiency, particularly in the large protein networks that you find in photosynthesis.”
She used other spectroscopic techniques as well to study how proteins rapidly change their conformation when they bind to specific targets, such as when receptors found on cell surfaces bind to stimuli like growth factors or other signaling molecules.
Schlau-Cohen enjoyed chemistry as a high school student and was particularly intrigued by the phenomenon known as wave-particle duality, a concept whereby physical matter can have both wave-like and particle-like properties. She used ultrafast microscopy, at Brown University where she majored in chemical physics, to study rapid processes such as energy moving between the electronic state of molecules.
The associate professor intends to develop nanostructures with similar or even better emergent properties than photosynthetic light-harvesting systems. Schlau-Cohen wants to achieve control over the evolution of light energy in a way that mimics or even exceeds the performance of nature.
