Monitoring picosecond events in photosynthesis
- First steps in photosynthesis take place on a picosecond (ps) time scale and are crucial for the efficiency of capturing sunlight and transforming the light energy into chemical energy (biofuels).
- Ultrafast kinetics of these events can be studied with fluorescence measurements on a streak-camera system. Fluorescence spectra are recorded with ps time resolution and show how excitation energy flows through the photosynthetic system, how fast it goes and what the efficiency is in different conditions.
- A streak-camera image (C) is shown that reflects the first events in cyanobacteria (B). The cartoon (A) shows the organization of the different pigment-protein complexes in these cyanobacteria and the corresponding spectra and time constants (please ask a nearby biophysicist for explanation).
- •Key point of single‐molecule fluorescence spectroscopy (SMFS) is its ultra high sensitivity (D) : single photons emitted from single fluorophores can be detected with high temporal and spatial resolution!
- Single-molecule experiments on biological objects can be performed under biologically relevant conditions and can reveal information about dynamic or static heterogeneity and the possible existence of sub‐populations.
- Single‐molecule FRET or super‐resolution microscopy are expected to dramatically expand our knowledge of biological processes on the molecular level.