Ultrafast energy relaxation in single light-harvesting complexes
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10333730" target="_blank" >RIV/00216208:11320/16:10333730 - isvavai.cz</a>
Výsledek na webu
<a href="http://dx.doi.org/10.1073/pnas.1522265113" target="_blank" >http://dx.doi.org/10.1073/pnas.1522265113</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1073/pnas.1522265113" target="_blank" >10.1073/pnas.1522265113</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
Ultrafast energy relaxation in single light-harvesting complexes
Popis výsledku v původním jazyce
Energy relaxation in light-harvesting complexes has been extensively studied by various ultrafast spectroscopic techniques, the fastest processes being in the sub-100-fs range. At the same time, much slower dynamics have been observed in individual complexes by single-molecule fluorescence spectroscopy (SMS). In this work, we use a pump-probe-type SMS technique to observe the ultrafast en- ergy relaxation in single light-harvesting complexes LH2 of purple bacteria. After excitation at 800 nm, the measured relaxation time distribution of multiple complexes has a peak at 95 fs and is asym- metric, with a tail at slower relaxation times. When tuning the exci- tation wavelength, the distribution changes in both its shape and position. The observed behavior agrees with what is to be expected from the LH2 excited states structure. As we show by a Redfield theory calculation of the relaxation times, the distribution shape cor- responds to the expected effect of Gaussian disorder of the pigment transition energies. By repeatedly measuring few individual com- plexes for minutes, we find that complexes sample the relaxation time distribution on a timescale of seconds. Furthermore, by compar- ing the distribution from a single long-lived complex with the whole ensemble, we demonstrate that, regarding the relaxation times, the ensemble can be considered ergodic. Our findings thus agree with the commonly used notion of an ensemble of identical LH2 complexes experiencing slow random fluctuations.
Název v anglickém jazyce
Ultrafast energy relaxation in single light-harvesting complexes
Popis výsledku anglicky
Energy relaxation in light-harvesting complexes has been extensively studied by various ultrafast spectroscopic techniques, the fastest processes being in the sub-100-fs range. At the same time, much slower dynamics have been observed in individual complexes by single-molecule fluorescence spectroscopy (SMS). In this work, we use a pump-probe-type SMS technique to observe the ultrafast en- ergy relaxation in single light-harvesting complexes LH2 of purple bacteria. After excitation at 800 nm, the measured relaxation time distribution of multiple complexes has a peak at 95 fs and is asym- metric, with a tail at slower relaxation times. When tuning the exci- tation wavelength, the distribution changes in both its shape and position. The observed behavior agrees with what is to be expected from the LH2 excited states structure. As we show by a Redfield theory calculation of the relaxation times, the distribution shape cor- responds to the expected effect of Gaussian disorder of the pigment transition energies. By repeatedly measuring few individual com- plexes for minutes, we find that complexes sample the relaxation time distribution on a timescale of seconds. Furthermore, by compar- ing the distribution from a single long-lived complex with the whole ensemble, we demonstrate that, regarding the relaxation times, the ensemble can be considered ergodic. Our findings thus agree with the commonly used notion of an ensemble of identical LH2 complexes experiencing slow random fluctuations.
Klasifikace
Druh
J<sub>x</sub> - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)
CEP obor
CF - Fyzikální chemie a teoretická chemie
OECD FORD obor
—
Návaznosti výsledku
Projekt
<a href="/cs/project/GA14-25752S" target="_blank" >GA14-25752S: Mikroskopické enviromentální determinanty a samoregulace přenosu energie ve fotosyntéze</a><br>
Návaznosti
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Ostatní
Rok uplatnění
2016
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Proceedings of the National Academy of Sciences of the United States of America
ISSN
0027-8424
e-ISSN
—
Svazek periodika
2016
Číslo periodika v rámci svazku
113
Stát vydavatele periodika
US - Spojené státy americké
Počet stran výsledku
6
Strana od-do
2934-2939
Kód UT WoS článku
000372014200051
EID výsledku v databázi Scopus
2-s2.0-84962554260