Dark States in the Light-Harvesting complex 2 Revealed by Two-dimensional Electronic Spectroscopy

M. Ferretti, R.J.G. Hendrikx, E. Romero Mesa, J. Southall, R.J. Cogdell, V.I. Novoderezhkin, G.D. Scholes, R. van Grondelle

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

Energy transfer and trapping in the light harvesting antennae of purple photosynthetic bacteria is an ultrafast process, which occurs with a quantum efficiency close to unity. However the mechanisms behind this process have not yet been fully understood. Recently it was proposed that low-lying energy dark states, such as charge transfer states and polaron pairs, play an important role in the dynamics and directionality of energy transfer. However, it is difficult to directly detect those states because of their small transition dipole moment and overlap with the B850/B870 exciton bands. Here we present a new experimental approach, which combines the selectivity of two-dimensional electronic spectroscopy with the availability of genetically modified light harvesting complexes, to reveal the presence of those dark states in both the genetically modified and the wild-type light harvesting 2 complexes of Rhodopseudomonas palustris. We suggest that Nature has used the unavoidable charge transfer processes that occur when LH pigments are concentrated to enhance and direct the flow of energy.
Original languageEnglish
Article number20834
JournalScientific Reports
Volume6
DOIs
Publication statusPublished - 2016

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Spectroscopy
Energy transfer
Charge transfer
Gene Conversion
Dipole moment
Quantum efficiency
Pigments
Bacteria
Availability
Antennas
LDS 751

Cite this

Ferretti, M. ; Hendrikx, R.J.G. ; Romero Mesa, E. ; Southall, J. ; Cogdell, R.J. ; Novoderezhkin, V.I. ; Scholes, G.D. ; van Grondelle, R. / Dark States in the Light-Harvesting complex 2 Revealed by Two-dimensional Electronic Spectroscopy. In: Scientific Reports. 2016 ; Vol. 6.
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abstract = "Energy transfer and trapping in the light harvesting antennae of purple photosynthetic bacteria is an ultrafast process, which occurs with a quantum efficiency close to unity. However the mechanisms behind this process have not yet been fully understood. Recently it was proposed that low-lying energy dark states, such as charge transfer states and polaron pairs, play an important role in the dynamics and directionality of energy transfer. However, it is difficult to directly detect those states because of their small transition dipole moment and overlap with the B850/B870 exciton bands. Here we present a new experimental approach, which combines the selectivity of two-dimensional electronic spectroscopy with the availability of genetically modified light harvesting complexes, to reveal the presence of those dark states in both the genetically modified and the wild-type light harvesting 2 complexes of Rhodopseudomonas palustris. We suggest that Nature has used the unavoidable charge transfer processes that occur when LH pigments are concentrated to enhance and direct the flow of energy.",
author = "M. Ferretti and R.J.G. Hendrikx and {Romero Mesa}, E. and J. Southall and R.J. Cogdell and V.I. Novoderezhkin and G.D. Scholes and {van Grondelle}, R.",
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Dark States in the Light-Harvesting complex 2 Revealed by Two-dimensional Electronic Spectroscopy. / Ferretti, M.; Hendrikx, R.J.G.; Romero Mesa, E.; Southall, J.; Cogdell, R.J.; Novoderezhkin, V.I.; Scholes, G.D.; van Grondelle, R.

In: Scientific Reports, Vol. 6, 20834, 2016.

Research output: Contribution to JournalArticleAcademicpeer-review

TY - JOUR

T1 - Dark States in the Light-Harvesting complex 2 Revealed by Two-dimensional Electronic Spectroscopy

AU - Ferretti, M.

AU - Hendrikx, R.J.G.

AU - Romero Mesa, E.

AU - Southall, J.

AU - Cogdell, R.J.

AU - Novoderezhkin, V.I.

AU - Scholes, G.D.

AU - van Grondelle, R.

PY - 2016

Y1 - 2016

N2 - Energy transfer and trapping in the light harvesting antennae of purple photosynthetic bacteria is an ultrafast process, which occurs with a quantum efficiency close to unity. However the mechanisms behind this process have not yet been fully understood. Recently it was proposed that low-lying energy dark states, such as charge transfer states and polaron pairs, play an important role in the dynamics and directionality of energy transfer. However, it is difficult to directly detect those states because of their small transition dipole moment and overlap with the B850/B870 exciton bands. Here we present a new experimental approach, which combines the selectivity of two-dimensional electronic spectroscopy with the availability of genetically modified light harvesting complexes, to reveal the presence of those dark states in both the genetically modified and the wild-type light harvesting 2 complexes of Rhodopseudomonas palustris. We suggest that Nature has used the unavoidable charge transfer processes that occur when LH pigments are concentrated to enhance and direct the flow of energy.

AB - Energy transfer and trapping in the light harvesting antennae of purple photosynthetic bacteria is an ultrafast process, which occurs with a quantum efficiency close to unity. However the mechanisms behind this process have not yet been fully understood. Recently it was proposed that low-lying energy dark states, such as charge transfer states and polaron pairs, play an important role in the dynamics and directionality of energy transfer. However, it is difficult to directly detect those states because of their small transition dipole moment and overlap with the B850/B870 exciton bands. Here we present a new experimental approach, which combines the selectivity of two-dimensional electronic spectroscopy with the availability of genetically modified light harvesting complexes, to reveal the presence of those dark states in both the genetically modified and the wild-type light harvesting 2 complexes of Rhodopseudomonas palustris. We suggest that Nature has used the unavoidable charge transfer processes that occur when LH pigments are concentrated to enhance and direct the flow of energy.

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