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Thermoluminescence: theory.
Fabrice Rappaport1, Jérôme Lavergne
1Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique, Université Paris 6, 13 Rue Pierre et Marie Curie, Paris, France. Fabrice.Rappaport@ibpc.fr
Photosynthesis Research
|June 18, 2009
Summary
Thermoluminescence (TL) probes radical pair de-trapping in photosynthesis. Modified theory explains how TL emission lags radical pair decay, with integrated luminescence increasing with heating rate.
Area of Science:
- Photosynthesis research
- Biophysics
- Solid-state physics applications
Background:
- Thermoluminescence (TL) is used to study photosynthetic reaction centers.
- Original TL theory assumes recombination equals light emission, which differs in photosynthetic systems.
- Photosynthetic recombination involves multiple pathways, with radiative routes being minor.
Purpose of the Study:
- To modify TL theory for photosynthetic systems.
- To investigate the influence of redox potentials on TL emission characteristics.
- To analyze the impact of light-harvesting antenna connectivity on thermoluminescence.
Main Methods:
- Theoretical modeling of thermoluminescence in photosynthetic systems.
- Comparison of theoretical predictions with experimental data from Photosystem II mutants.
- Analysis of the effect of heating rate on integrated luminescence.
Main Results:
- The radiative pathway in photosynthesis has higher activation energy, causing TL peaks to lag behind radical pair decay.
- Integrated luminescence intensity increases with the heating rate.
- Theoretical predictions show good agreement with experimental studies on Photosystem II mutants regarding redox potential effects.
Conclusions:
- The modified TL theory accurately describes thermoluminescence in photosynthetic systems.
- Redox potentials of cofactors significantly influence TL emission characteristics.
- Light-harvesting antenna connectivity has a minimal effect on TL, unlike room-temperature luminescence kinetics.
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