Electronic Spectroscopy

The Service de Bioénergétique, Biologie Structurale et Mécanismes (SB2SM) / CNRS-UMR8221, located at JOLIOT/CEA-Saclay, has a platform dedicated to the electronic spectroscopy of biological samples. Historically, we specialised in the study of photosynthesis/photophysics and over the years have accumulated a diverse range of commercially available spectrometers as well as home-built optical set-ups including a “Machine de Joliot”. In general, we are able to monitor spectroscopic changes at the protein level in intact cells on many time scales for research projects that wished to monitor absorption/fluorescence changes.
A special set-up was developed to monitor small flash-induced transient absorption changes with a time resolution of 300 ps in single flash experiments, or with a very modest number of averaged experiments.
Commercial spectrometers are available to measure chlorophyll fluorescence, P700 oxidation and NADPH fluorescence. Chlorophyll fluorescence and P700 can be measured in vivo using leaves or algae/cyanobacteria cultures. NADPH fluorescence can be measured in algae/cyanobacteria cultures or in isolated intact chloroplasts.
Thermoluminescence can be measured with a home-built set-up that is able to monitor charge recombination reactions in photosystem II. This method can be used for leaves, algae/cyanobacteria cultures as well as isolated photosytem II.