Comparison of excitation energy transfer in cyanobacterial photosystem I in solution and immobilized on conducting glass

Sebastian Szewczyk, Wojciech Giera, Sandrine D'Haene, Rienk van Grondelle, Krzysztof Gibasiewicz

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

Excitation energy transfer in monomeric and trimeric forms of photosystem I (PSI) from the cyanobacterium Synechocystis sp. PCC 6803 in solution or immobilized on FTO conducting glass was compared using time-resolved fluorescence. Deposition of PSI on glass preserves bi-exponential excitation decay of similar to 4-7 and similar to 21-25 ps lifetimes characteristic of PSI in solution. The faster phase was assigned in part to photochemical quenching (charge separation) of excited bulk chlorophylls and in part to energy transfer from bulk to low-energy (red) chlorophylls. The slower phase was assigned to photochemical quenching of the excitation equilibrated over bulk and red chlorophylls. The main differences between dissolved and immobilized PSI (iPSI) are: (1) the average excitation decay in iPSI is about 11 ps, which is faster by a few ps than for PSI in solution due to significantly faster excitation quenching of bulk chlorophylls by charge separation (similar to 10 ps instead of similar to 15 ps) accompanied by slightly weaker coupling of bulk and red chlorophylls; (2) the number of red chlorophylls in monomeric PSI increases twice-from 3 in solution to 6 after immobilization-as a result of interaction with neighboring monomers and conducting glass; despite the increased number of red chlorophylls, the excitation decay accelerates in iPSI; (3) the number of red chlorophylls in trimeric PSI is 4 (per monomer) and remains unchanged after immobilization; (4) in all the samples under study, the free energy gap between mean red (emission at similar to 710 nm) and mean bulk (emission at similar to 686 nm) emitting states of chlorophylls was estimated at a similar level of 17-27 meV. All these observations indicate that despite slight modifications, dried PSI complexes adsorbed on the FTO surface remain fully functional in terms of excitation energy transfer and primary charge separation that is particularly important in the view of photovoltaic applications of this photosystem.
Original languageEnglish
Pages (from-to)111-126
JournalPhotosynthesis Research
Volume132
Issue number2
DOIs
Publication statusPublished - May 2017

Keywords

  • Photosystem I
  • Time-resolved fluorescence
  • Streak camera
  • Excitation energy transfer
  • Cyanobacteria
  • Photovoltaics
  • Biophotovoltaics
  • Red chlorophylls

Cite this

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title = "Comparison of excitation energy transfer in cyanobacterial photosystem I in solution and immobilized on conducting glass",
abstract = "Excitation energy transfer in monomeric and trimeric forms of photosystem I (PSI) from the cyanobacterium Synechocystis sp. PCC 6803 in solution or immobilized on FTO conducting glass was compared using time-resolved fluorescence. Deposition of PSI on glass preserves bi-exponential excitation decay of similar to 4-7 and similar to 21-25 ps lifetimes characteristic of PSI in solution. The faster phase was assigned in part to photochemical quenching (charge separation) of excited bulk chlorophylls and in part to energy transfer from bulk to low-energy (red) chlorophylls. The slower phase was assigned to photochemical quenching of the excitation equilibrated over bulk and red chlorophylls. The main differences between dissolved and immobilized PSI (iPSI) are: (1) the average excitation decay in iPSI is about 11 ps, which is faster by a few ps than for PSI in solution due to significantly faster excitation quenching of bulk chlorophylls by charge separation (similar to 10 ps instead of similar to 15 ps) accompanied by slightly weaker coupling of bulk and red chlorophylls; (2) the number of red chlorophylls in monomeric PSI increases twice-from 3 in solution to 6 after immobilization-as a result of interaction with neighboring monomers and conducting glass; despite the increased number of red chlorophylls, the excitation decay accelerates in iPSI; (3) the number of red chlorophylls in trimeric PSI is 4 (per monomer) and remains unchanged after immobilization; (4) in all the samples under study, the free energy gap between mean red (emission at similar to 710 nm) and mean bulk (emission at similar to 686 nm) emitting states of chlorophylls was estimated at a similar level of 17-27 meV. All these observations indicate that despite slight modifications, dried PSI complexes adsorbed on the FTO surface remain fully functional in terms of excitation energy transfer and primary charge separation that is particularly important in the view of photovoltaic applications of this photosystem.",
keywords = "Photosystem I, Time-resolved fluorescence, Streak camera, Excitation energy transfer, Cyanobacteria, Photovoltaics, Biophotovoltaics, Red chlorophylls",
author = "Sebastian Szewczyk and Wojciech Giera and Sandrine D'Haene and {van Grondelle}, Rienk and Krzysztof Gibasiewicz",
year = "2017",
month = "5",
doi = "10.1007/s11120-016-0312-4",
language = "English",
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pages = "111--126",
journal = "Photosynthesis Research",
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Comparison of excitation energy transfer in cyanobacterial photosystem I in solution and immobilized on conducting glass. / Szewczyk, Sebastian; Giera, Wojciech; D'Haene, Sandrine; van Grondelle, Rienk; Gibasiewicz, Krzysztof.

In: Photosynthesis Research, Vol. 132, No. 2, 05.2017, p. 111-126.

Research output: Contribution to JournalArticleAcademicpeer-review

TY - JOUR

T1 - Comparison of excitation energy transfer in cyanobacterial photosystem I in solution and immobilized on conducting glass

AU - Szewczyk, Sebastian

AU - Giera, Wojciech

AU - D'Haene, Sandrine

AU - van Grondelle, Rienk

AU - Gibasiewicz, Krzysztof

PY - 2017/5

Y1 - 2017/5

N2 - Excitation energy transfer in monomeric and trimeric forms of photosystem I (PSI) from the cyanobacterium Synechocystis sp. PCC 6803 in solution or immobilized on FTO conducting glass was compared using time-resolved fluorescence. Deposition of PSI on glass preserves bi-exponential excitation decay of similar to 4-7 and similar to 21-25 ps lifetimes characteristic of PSI in solution. The faster phase was assigned in part to photochemical quenching (charge separation) of excited bulk chlorophylls and in part to energy transfer from bulk to low-energy (red) chlorophylls. The slower phase was assigned to photochemical quenching of the excitation equilibrated over bulk and red chlorophylls. The main differences between dissolved and immobilized PSI (iPSI) are: (1) the average excitation decay in iPSI is about 11 ps, which is faster by a few ps than for PSI in solution due to significantly faster excitation quenching of bulk chlorophylls by charge separation (similar to 10 ps instead of similar to 15 ps) accompanied by slightly weaker coupling of bulk and red chlorophylls; (2) the number of red chlorophylls in monomeric PSI increases twice-from 3 in solution to 6 after immobilization-as a result of interaction with neighboring monomers and conducting glass; despite the increased number of red chlorophylls, the excitation decay accelerates in iPSI; (3) the number of red chlorophylls in trimeric PSI is 4 (per monomer) and remains unchanged after immobilization; (4) in all the samples under study, the free energy gap between mean red (emission at similar to 710 nm) and mean bulk (emission at similar to 686 nm) emitting states of chlorophylls was estimated at a similar level of 17-27 meV. All these observations indicate that despite slight modifications, dried PSI complexes adsorbed on the FTO surface remain fully functional in terms of excitation energy transfer and primary charge separation that is particularly important in the view of photovoltaic applications of this photosystem.

AB - Excitation energy transfer in monomeric and trimeric forms of photosystem I (PSI) from the cyanobacterium Synechocystis sp. PCC 6803 in solution or immobilized on FTO conducting glass was compared using time-resolved fluorescence. Deposition of PSI on glass preserves bi-exponential excitation decay of similar to 4-7 and similar to 21-25 ps lifetimes characteristic of PSI in solution. The faster phase was assigned in part to photochemical quenching (charge separation) of excited bulk chlorophylls and in part to energy transfer from bulk to low-energy (red) chlorophylls. The slower phase was assigned to photochemical quenching of the excitation equilibrated over bulk and red chlorophylls. The main differences between dissolved and immobilized PSI (iPSI) are: (1) the average excitation decay in iPSI is about 11 ps, which is faster by a few ps than for PSI in solution due to significantly faster excitation quenching of bulk chlorophylls by charge separation (similar to 10 ps instead of similar to 15 ps) accompanied by slightly weaker coupling of bulk and red chlorophylls; (2) the number of red chlorophylls in monomeric PSI increases twice-from 3 in solution to 6 after immobilization-as a result of interaction with neighboring monomers and conducting glass; despite the increased number of red chlorophylls, the excitation decay accelerates in iPSI; (3) the number of red chlorophylls in trimeric PSI is 4 (per monomer) and remains unchanged after immobilization; (4) in all the samples under study, the free energy gap between mean red (emission at similar to 710 nm) and mean bulk (emission at similar to 686 nm) emitting states of chlorophylls was estimated at a similar level of 17-27 meV. All these observations indicate that despite slight modifications, dried PSI complexes adsorbed on the FTO surface remain fully functional in terms of excitation energy transfer and primary charge separation that is particularly important in the view of photovoltaic applications of this photosystem.

KW - Photosystem I

KW - Time-resolved fluorescence

KW - Streak camera

KW - Excitation energy transfer

KW - Cyanobacteria

KW - Photovoltaics

KW - Biophotovoltaics

KW - Red chlorophylls

U2 - 10.1007/s11120-016-0312-4

DO - 10.1007/s11120-016-0312-4

M3 - Article

VL - 132

SP - 111

EP - 126

JO - Photosynthesis Research

JF - Photosynthesis Research

SN - 0166-8595

IS - 2

ER -