1
|
López-Ortiz M, Bolzonello L, Bruschi M, Fresch E, Collini E, Hu C, Croce R, van Hulst NF, Gorostiza P. Photoelectrochemical Two-Dimensional Electronic Spectroscopy (PEC2DES) of Photosystem I: Charge Separation Dynamics Hidden in a Multichromophoric Landscape. ACS APPLIED MATERIALS & INTERFACES 2024; 16:43451-43461. [PMID: 39121384 PMCID: PMC11345722 DOI: 10.1021/acsami.4c03652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 07/26/2024] [Accepted: 08/02/2024] [Indexed: 08/11/2024]
Abstract
We present a nonlinear spectroelectrochemical technique to investigate photosynthetic protein complexes. The PEC2DES setup combines photoelectrochemical detection (PEC) that selectively probes the protein photogenerated charges output with two-dimensional electronic spectroscopy (2DES) excitation that spreads the nonlinear optical response of the system in an excitation-detection map. PEC allows us to distinguish the contribution of charge separation (CS) from other de-excitation pathways, whereas 2DES allows us to disentangle congested spectral bands and evaluate the exciton dynamics (decays and coherences) of the photosystem complex. We have developed in operando phase-modulated 2DES by measuring the photoelectrochemical reaction rate in a biohybrid electrode functionalized with a plant photosystem complex I-light harvesting complex I (PSI-LHCI) layer. Optimizing the photoelectrochemical current signal yields reliable linear spectra unequivocally associated with PSI-LHCI. The 2DES signal is validated by nonlinear features like the characteristic vibrational coherence at 750 cm-1. However, no energy transfer dynamics is observed within the 450 fs experimental window. These intriguing results are discussed in the context of incoherent mixing resulting in reduced nonlinear contrast for multichromophoric complexes, such as the 160 chlorophyll PSI. The presented PEC2DES method identifies generated charges unlike purely optical 2DES and opens the way to probe the CS channel in multichromophoric complexes.
Collapse
Affiliation(s)
- Manuel López-Ortiz
- Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of
Science and Technology, Barcelona 08028, Spain
| | - Luca Bolzonello
- ICFO
- Institut de Ciències Fotòniques, The Barcelona Institute
of Science and Technology, Castelldefels, Barcelona 08860, Spain
| | - Matteo Bruschi
- Dipartimento
di Scienze Chimiche, Università degli
Studi di Padova, Padova 35131, Italy
| | - Elisa Fresch
- Dipartimento
di Scienze Chimiche, Università degli
Studi di Padova, Padova 35131, Italy
| | - Elisabetta Collini
- Dipartimento
di Scienze Chimiche, Università degli
Studi di Padova, Padova 35131, Italy
| | - Chen Hu
- Biophysics
of Photosynthesis, Department of Physics and Astronomy, Faculty of
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, Amsterdam, HV 1081, The Netherlands
| | - Roberta Croce
- Biophysics
of Photosynthesis, Department of Physics and Astronomy, Faculty of
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, Amsterdam, HV 1081, The Netherlands
| | - Niek F. van Hulst
- ICFO
- Institut de Ciències Fotòniques, The Barcelona Institute
of Science and Technology, Castelldefels, Barcelona 08860, Spain
- ICREA
- Institució Catalana de Recerca i Estudis Avançats, Barcelona 08010, Spain
| | - Pau Gorostiza
- Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of
Science and Technology, Barcelona 08028, Spain
- ICREA
- Institució Catalana de Recerca i Estudis Avançats, Barcelona 08010, Spain
- CIBER-BBN, Barcelona 08028, Spain
| |
Collapse
|
2
|
Andreou C, Tselios C, Ioannou A, Varotsis C. Probing the Fucoxanthin-Chlorophyll a/ c-Binding Proteins (FCPs) of the Marine Diatom Fragilariopsis sp. by Resonance Raman Spectroscopy. J Phys Chem B 2023; 127:9014-9020. [PMID: 37819729 PMCID: PMC10614187 DOI: 10.1021/acs.jpcb.3c04346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/21/2023] [Indexed: 10/13/2023]
Abstract
We report resonance Raman spectra of the light-harvesting fucoxanthin-chlorophyll a/c-binding proteins (FCPs) of marine diatom Fragilariopsis sp. The Raman shifts in the 15N-isotope-enriched diatom provide the first spectroscopic evidence for the characterization of the Ca-N marker bands and, thus, of the penta- and hexacoordinated states of chlorophylls a/c in the FCPs. Under 405 and 442 nm Raman excitations, all of the marker bands of Chl a/c are observed and the isotope-based assignments provide new information concerning the structure of Chls a/c in the FCPs and their interactions with the protein environment. Therefore, the Raman spectrum at 405 nm originates from the π-π* transitions of Chl a/c and not from a different, non π-π* electronic transition, as previously reported (BBA Bioenergetics, 2010, 1797, 1647-1656). Based on the 15N isotope shifts of the Ca-N and in conjunction with other marker bands, two distinct conformations of five- and six-coordinated Chl a and Chl c are observed. In addition, two keto carbonyls were observed at 1679 (strong H-bonded) and 1691 cm-1 (weak H-bonded) in both the 405 and 442 nm Raman spectra, respectively. Collectively, the results provide solid evidence of the nature of the vibrational modes of the active Chl a/c photosynthetic pigments in the FCPs.
Collapse
Affiliation(s)
- Charalampos Andreou
- Department of Chemical Engineering, Cyprus University of Technology, 95 Eirinis Str., Lemesos 3603, Cyprus
| | - Charalampos Tselios
- Department of Chemical Engineering, Cyprus University of Technology, 95 Eirinis Str., Lemesos 3603, Cyprus
| | - Aristos Ioannou
- Department of Chemical Engineering, Cyprus University of Technology, 95 Eirinis Str., Lemesos 3603, Cyprus
| | - Constantinos Varotsis
- Department of Chemical Engineering, Cyprus University of Technology, 95 Eirinis Str., Lemesos 3603, Cyprus
| |
Collapse
|
3
|
Zhu R, Ruan M, Li H, Leng X, Zou J, Wang J, Chen H, Wang Z, Weng Y. Vibrational and vibronic coherences in the energy transfer process of light-harvesting complex II revealed by two-dimensional electronic spectroscopy. J Chem Phys 2022; 156:125101. [DOI: 10.1063/5.0082280] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The presence of quantum coherence in light-harvesting complex II (LHCII) as a mechanism to understand the efficiency of the light-harvesting function in natural photosynthetic systems is still debated due to its structural complexity and weak-amplitude coherent oscillations. Here, we revisit the coherent dynamics and clarify different types of coherences in the energy transfer processes of LHCII using a joint method of the high-S/N transient grating and two-dimensional electronic spectroscopy. We find that the electronic coherence decays completely within 50 fs at room temperature. The vibrational coherences of chlorophyll a dominate over oscillations within 1 ps, whereas a low-frequency mode of 340 cm−1 with a vibronic mixing character may participate in vibrationally assisted energy transfer between chlorophylls a. Our results may suggest that vibronic mixing is relevant for rapid energy transfer processes among chlorophylls in LHCII.
Collapse
Affiliation(s)
- Ruidan Zhu
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meixia Ruan
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Li
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuan Leng
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiading Zou
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiayu Wang
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hailong Chen
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Zhuan Wang
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuxiang Weng
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| |
Collapse
|
4
|
Zeng J, Ping W, Sanaeifar A, Xu X, Luo W, Sha J, Huang Z, Huang Y, Liu X, Zhan B, Zhang H, Li X. Quantitative visualization of photosynthetic pigments in tea leaves based on Raman spectroscopy and calibration model transfer. PLANT METHODS 2021; 17:4. [PMID: 33407678 PMCID: PMC7788994 DOI: 10.1186/s13007-020-00704-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 12/22/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND Photosynthetic pigments participating in the absorption, transformation and transfer of light energy play a very important role in plant growth. While, the spatial distribution of foliar pigments is an important indicator of environmental stress, such as pests, diseases and heavy metal stress. RESULTS In this paper, in situ quantitative visualization of chlorophyll and carotenoid was realized by combining the Raman spectroscopy with calibration model transfer, and a laboratory Raman spectral model was successfully extended to a portable field spectral measurement. Firstly, a nondestructive and fast model for determination of chlorophyll and carotenoid in tea leaf was established based on confocal micro-Raman spectrometer in the laboratory. Then the spectral model was extended to a real-time foliar map scanning spectra of a field portable Raman spectrometer through calibration model transfer, and the spectral variation between the confocal micro-Raman spectrometer in the laboratory and the portable Raman spectrometer were effectively corrected by the direct standardization (DS) algorithm. The portable map scanning Raman spectra of the tea leaves after the model transfer were got into the established quantitative determination model to predict the concentration of photosynthetic pigments at each pixel of the tea leaves. The predicted photosynthetic pigments concentration of each pixel was imaged to illustrate the distribution map of foliar pigments. Statistical analysis showed that the predicted pigment contents were highly correlated with the real contents. CONCLUSIONS It can be concluded that the Raman spectroscopy was applicable for in situ, non-destructive and rapid quantitative detecting and imaging of photosynthetic pigment concentration in tea leaves, and the spectral detection model established based on the laboratory Raman spectrometer can be applied to a portable field spectrometer for quantitatively imaging of the foliar pigments.
Collapse
Affiliation(s)
- Jianjun Zeng
- College of Electrical and Automation Engineering, East China Jiaotong University, Nanchang, 330013, China
| | - Wen Ping
- College of Electrical and Automation Engineering, East China Jiaotong University, Nanchang, 330013, China
| | - Alireza Sanaeifar
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Xiao Xu
- College of Electrical and Automation Engineering, East China Jiaotong University, Nanchang, 330013, China
| | - Wei Luo
- College of Electrical and Automation Engineering, East China Jiaotong University, Nanchang, 330013, China
| | - Junjing Sha
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Zhenxiong Huang
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yifeng Huang
- College of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, 330013, China
| | - Xuemei Liu
- College of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, 330013, China
| | - Baishao Zhan
- College of Electrical and Automation Engineering, East China Jiaotong University, Nanchang, 330013, China
| | - Hailiang Zhang
- College of Electrical and Automation Engineering, East China Jiaotong University, Nanchang, 330013, China.
| | - Xiaoli Li
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
| |
Collapse
|
5
|
Roy K, Ghosh D, Sarkar K, Devi P, Kumar P. Chlorophyll( a)/Carbon Quantum Dot Bio-Nanocomposite Activated Nano-Structured Silicon as an Efficient Photocathode for Photoelectrochemical Water Splitting. ACS APPLIED MATERIALS & INTERFACES 2020; 12:37218-37226. [PMID: 32814382 DOI: 10.1021/acsami.0c10279] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Solar-driven water splitting is considered as a futuristic sustainable way to generate hydrogen and chemical storage of solar energy. Further, considering the technological competence, silicon is one of the potential materials for developing large-scale and cost-effective photocathodes (PCs), but it lacks efficacy and stability. Here, we show that chlorophyll(a)/carbon quantum dots (Chl/CQDs) bio-nanocomposite (b-NC)-decorated Si-nanowires (SiNWs) as PC can surpass the reported efficiency for photoelectrochemical (PEC) hydrogen generation along with stability. The optimized heterojunction (Chl/CQDs_SiNW) significantly enhances broad-band solar absorption and protects Si surface from corrosion. Further, the appropriate band alignment enforces efficient photogenerated charge separation and possesses directional exciton transport property via the Förster resonance energy transfer (FRET) mechanism. This synergic effect demonstrates an ∼18 times increase in photocurrent density (26.36 mA/cm2) compared to pristine SiNW PC at 1.07 V vs reversible hydrogen electrode (RHE). The efficiency reaches ∼7.86%, which is comparably the highest reported for hybrid Si-based photocathodes. Hydrogen evaluation rate was measured to be ∼113 μmol/h at 0.8 V vs RHE under 1 sun illumination. With Si-process line compatibility, this new finding opens a new direction toward the development of Si-based efficient and stable PCs at a large scale for commercial applications.
Collapse
Affiliation(s)
- Krishnendu Roy
- School of Materials Science, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Dibyendu Ghosh
- School of Materials Science, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - K Sarkar
- School of Materials Science, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Pooja Devi
- Central Scientific Instruments Organization, Sector-30C, Chandigarh 160030, India
| | - Praveen Kumar
- School of Materials Science, Indian Association for the Cultivation of Science, Kolkata 700032, India
| |
Collapse
|
6
|
Rätsep M, Linnanto JM, Freiberg A. Higher Order Vibronic Sidebands of Chlorophyll a and Bacteriochlorophyll a for Enhanced Excitation Energy Transfer and Light Harvesting. J Phys Chem B 2019; 123:7149-7156. [PMID: 31356081 DOI: 10.1021/acs.jpcb.9b06843] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Optical absorption and fluorescence spectra of molecules in condensed phases often show extensive sidebands. Originating from electron-vibrational and electron-phonon couplings, these spectral tails bear important information on the dynamics of electronic states and processes the molecules are involved in. The vibronic sidebands observed in conjugate Qy absorption and fluorescence spectra of chlorophyll a and bacteriochlorophyll a are relatively weak, characterized by the total Huang-Rhys factor which is less than one. Therefore, it is widely considered that only fundamental intramolecular modes are responsible for their formation. Here, we provide evidence for extra-long and structured fluorescence tails of chlorophyll a and bacteriochlorophyll a as far as 4000 cm-1 from respective spectral origins, far beyond the frequency range of fundamental modes. According to quantum chemical simulations, these sidebands extending to ∼960 nm in chlorophyll a and ∼1140 nm in bacteriochlorophyll a into the infrared part of the optical spectrum are mainly contributed to by vibrational overtones of the fundamental modes. Because energy transfer and relaxation processes generally depend on vibronic overlap integrals, these findings potentially contribute to better understanding of many vital photo-induced phenomena, including photosynthetic light harvesting.
Collapse
Affiliation(s)
- Margus Rätsep
- Institute of Physics , University of Tartu , W. Ostwald Street 1 , 50411 Tartu , Estonia
| | - Juha Matti Linnanto
- Institute of Physics , University of Tartu , W. Ostwald Street 1 , 50411 Tartu , Estonia
| | - Arvi Freiberg
- Institute of Physics , University of Tartu , W. Ostwald Street 1 , 50411 Tartu , Estonia.,Institute of Molecular and Cell Biology , University of Tartu , Riia 23 , 51010 Tartu , Estonia.,Estonian Academy of Sciences , Kohtu 6 , 10130 Tallinn , Estonia
| |
Collapse
|
7
|
Raman and 2D electronic spectroscopies: A fruitful alliance for the investigation of ground and excited state vibrations in chlorophyll a. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
8
|
Meneghin E, Leonardo C, Volpato A, Bolzonello L, Collini E. Mechanistic insight into internal conversion process within Q-bands of chlorophyll a. Sci Rep 2017; 7:11389. [PMID: 28900171 PMCID: PMC5595816 DOI: 10.1038/s41598-017-11621-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/29/2017] [Indexed: 11/08/2022] Open
Abstract
The non-radiative relaxation of the excitation energy from higher energy states to the lowest energy state in chlorophylls is a crucial preliminary step for the process of photosynthesis. Despite the continuous theoretical and experimental efforts to clarify the ultrafast dynamics of this process, it still represents the object of an intense investigation because the ultrafast timescale and the congestion of the involved states makes its characterization particularly challenging. Here we exploit 2D electronic spectroscopy and recently developed data analysis tools to provide more detailed insights into the mechanism of internal conversion within the Q-bands of chlorophyll a. The measurements confirmed the timescale of the overall internal conversion rate (170 fs) and captured the presence of a previously unidentified ultrafast (40 fs) intermediate step, involving vibronic levels of the lowest excited state.
Collapse
Affiliation(s)
- Elena Meneghin
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Cristina Leonardo
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Andrea Volpato
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Luca Bolzonello
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | | |
Collapse
|
9
|
Hamer M, Rezzano IN. Classical Characterization Techniques to Reveal the Structural Model of Nanocomposites with Bimetallic Monolayers of Porphyrins. Inorg Chem 2016; 55:8595-602. [PMID: 27482597 DOI: 10.1021/acs.inorgchem.6b01136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nanocomposites with bimetallic monolayers of porphyrins were prepared. The well-ordered metalloporphyrin monolayers covalently linked to the gold surface produce an important increase of the B band (∼400 nm) shifted 20 nm relative to that of the related high-spin iron(III) complexes in solution. The position of the B band in the bimetallic architectures is highly dependent on the relative amount of the two porphyrins, showing the most significant shift for the SiO2/APTES/AuNp/Fe-TPyP&M-TPyP (1:1) (30 nm, M = Ni(II) or Cu(II)). Resonance Raman based on the oxidation state marker bands (1553, 1354, and 390 cm(-1)) indicates that Fe-TPyP attached on gold nanoparticles adopts a low-spin Fe(II) conformation, which changes to Fe(II) intermediate spin or a low-spin Fe(III) in the presence of Cu-TPyP or Ni-TPyP. Surface-enhanced Raman scattering studies confirmed the hypothesis. MALDI-TOF analysis of the composites on gold nanoparticles was very useful in the detection of oxygenated forms of the metal complexes.
Collapse
Affiliation(s)
- Mariana Hamer
- Universidad de Buenos Aires , Facultad de Farmacia y Bioquı́mica, CONICET-IQUIFIB, Junin 956, CP 1113 Buenos Aires, Argentina
| | - Irene N Rezzano
- Universidad de Buenos Aires , Facultad de Farmacia y Bioquı́mica, CONICET-IQUIFIB, Junin 956, CP 1113 Buenos Aires, Argentina
| |
Collapse
|
10
|
Kosumi D, Nishiguchi T, Sugisaki M, Hashimoto H. Ultrafast coherent spectroscopic investigation on photosynthetic pigment chlorophyll a utilizing 20 fs pulses. J Photochem Photobiol A Chem 2015. [DOI: 10.1016/j.jphotochem.2015.06.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
11
|
O’Reilly EJ, Olaya-Castro A. Non-classicality of the molecular vibrations assisting exciton energy transfer at room temperature. Nat Commun 2014; 5:3012. [PMID: 24402469 PMCID: PMC3896760 DOI: 10.1038/ncomms4012] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 11/25/2013] [Indexed: 11/09/2022] Open
Abstract
Advancing the debate on quantum effects in light-initiated reactions in biology requires clear identification of non-classical features that these processes can exhibit and utilize. Here we show that in prototype dimers present in a variety of photosynthetic antennae, efficient vibration-assisted energy transfer in the sub-picosecond timescale and at room temperature can manifest and benefit from non-classical fluctuations of collective pigment motions. Non-classicality of initially thermalized vibrations is induced via coherent exciton-vibration interactions and is unambiguously indicated by negativities in the phase-space quasi-probability distribution of the effective collective mode coupled to the electronic dynamics. These quantum effects can be prompted upon incoherent input of excitation. Our results therefore suggest that investigation of the non-classical properties of vibrational motions assisting excitation and charge transport, photoreception and chemical sensing processes could be a touchstone for revealing a role for non-trivial quantum phenomena in biology.
Collapse
Affiliation(s)
- Edward J. O’Reilly
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
| | - Alexandra Olaya-Castro
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
| |
Collapse
|
12
|
Du J, Nakata K, Jiang Y, Tokunaga E, Kobayashi T. Spectral modulation observed in Chl-a by ultrafast laser spectroscopy. OPTICS EXPRESS 2011; 19:22480-22485. [PMID: 22109125 DOI: 10.1364/oe.19.022480] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Broadband real-time dynamic vibronic coupling in Chl-a were experimentally studied using few cycle laser pulses of 6.8fs duration and a 128-channnel lock-in amplifier. Thanks to the extreme temporal resolution benefitting from the ultrashort laser pulse, the real-time modulation of the electronic transition energy induced by the molecular vibrations were calculated by the time dependent first moments of the bleaching band. The transition energy was found to be modulated periodically with the same frequencies of molecular vibration found in the Fourier amplitude spectrum of the difference absorbance real-time traces. This was interpreted to be due to the difference in the effective transition energy associated with the wavepacket motion induced by the equilibrium positions of potential curves between the ground state and the excited state. Using the values, Huang-Rhys factors for several vibrational modes involved in the spectral modulation at the room-temperature have been determined.
Collapse
Affiliation(s)
- Juan Du
- Advanced Ultrafast Laser Research Center, and Department of Engineering Science, Faculty of Informatics and Engineering, University of Electro-Communications, 1-5-1, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
| | | | | | | | | |
Collapse
|
13
|
Real-time vibrational dynamics in chlorophyll a studied with a few-cycle pulse laser. Biophys J 2011; 101:995-1003. [PMID: 21843492 DOI: 10.1016/j.bpj.2011.07.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 07/12/2011] [Accepted: 07/14/2011] [Indexed: 11/20/2022] Open
Abstract
We use a 6.8-fs laser as the light source for broad-band femtosecond pump-probe real-time vibrational spectroscopy to investigate both electronic relaxation and vibrational dynamics of the Q(y)-band of Chl-a at 293 K. More than 25 vibrational modes coupled to the Q(y) transition are observed. Eleven of them have been clarified predominantly due to the excited state, and six of them are concluded to be nearly exclusively resulting from the ground-state wave-packet motion. Moreover, thanks to the broad-band detection over 5000 cm⁻¹, the modulated signals due to the excited state vibrational coherence are observed on both sides of the 0-0 transition with equal separation. The corresponding nonlinear process has been studied using a three-level model, from which the probe wavelength dependence of the phase of the periodic modulation can be calculated. The probe wavelength dependence of the vibrational amplitude is interpreted in terms of the interaction between the "pump" or "laser," Stokes, and anti-Stokes field intermediated by the molecular vibrations. In addition, an excited state absorption peak at ~709 nm has been observed. To the best of our knowledge, this is the first study of broad-band real-time vibrational spectroscopy in Chl-a.
Collapse
|
14
|
Kee HL, Kirmaier C, Tang Q, Diers JR, Muthiah C, Taniguchi M, Laha JK, Ptaszek M, Lindsey JS, Bocian DF, Holten D. Effects of Substituents on Synthetic Analogs of Chlorophylls. Part 1: Synthesis, Vibrational Properties and Excited-state Decay Characteristics. Photochem Photobiol 2007; 83:1110-24. [PMID: 17880506 DOI: 10.1111/j.1751-1097.2007.00150.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding the effects of substituents on the spectra of chlorins is essential for a wide variety of applications. Recent developments in synthetic methodology have made possible systematic studies of the properties of the chlorin macrocycle as a function of diverse types and patterns of substituents. In this paper, the spectral, vibrational and excited-state decay characteristics are examined for a set of synthetic chlorins. The chlorins bear substituents at the 5,10,15 (meso) positions or the 3,13 (beta) positions (plus 10-mesityl in a series of compounds) and include 24 zinc chlorins, 18 free base (Fb) analogs and one Fb or zinc oxophorbine. The oxophorbine contains the keto-bearing isocyclic ring present in the natural photosynthetic pigments (e.g. chlorophyll a). The substituents cause no significant perturbation to the structure of the chlorin macrocycle, as evidenced by the vibrational properties investigated using resonance Raman spectroscopy. In contrast, the fluorescence properties are significantly altered due to the electronic effects of substituents. For example, the fluorescence wavelength maximum, quantum yield and lifetime for a zinc chlorin bearing 3,13-diacetyl and 10-mesityl groups (662 nm, 0.28, 6.0 ns) differ substantially from those of the parent unsubstituted chlorin (602 nm, 0.062, 1.7 ns). Each of these properties of the lowest singlet excited state can be progressively stepped between these two extremes by incorporating different substituents. These perturbations are associated with significant changes in the rate constants of the decay pathways of the lowest excited singlet state. In this regard, the zinc chlorins with the red-most fluorescence also have the greatest radiative decay rate constant and are expected to have the fastest nonradiative internal conversion to the ground state. Nonetheless, these complexes have the longest singlet excited-state lifetime. The Fb chlorins bearing the same substituents exhibit similar fluorescence properties. Such combinations of factors render the chlorins suitable for a range of applications that require tunable coverage of the solar spectrum, long-lived excited states and red-region fluorescence.
Collapse
Affiliation(s)
- Hooi Ling Kee
- Department of Chemistry, Washington University, St. Louis, MO, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Saito K, Mukai K, Sumi H. Excited states of pigments in photosystem II reaction centers of photosynthesis: Characterization into a central dimer and remaining monomers. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2004.11.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
16
|
McCamant DW, Kukura P, Yoon S, Mathies RA. Femtosecond broadband stimulated Raman spectroscopy: Apparatus and methods. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2004; 75:4971-80. [PMID: 17183413 PMCID: PMC1712672 DOI: 10.1063/1.1807566] [Citation(s) in RCA: 208] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The laser, detection system, and methods that enable femtosecond broadband stimulated Raman spectroscopy (FSRS) are presented in detail. FSRS is a unique tool for obtaining high time resolution (<100 fs) vibrational spectra with an instrument response limited frequency resolution of <10 cm(-1). A titanium:Sapphire-based laser system produces the three different pulses needed for FSRS: (1) A femtosecond visible actinic pump that initiates the photochemistry, (2) a narrow bandwidth picosecond Raman pump that provides the energy reservoir for amplification of the probe, and (3) a femtosecond continuum probe that is amplified at Raman resonances shifted from the Raman pump. The dependence of the stimulated Raman signal on experimental parameters is explored, demonstrating the expected exponential increase in Raman intensity with concentration, pathlength, and Raman pump power. Raman spectra collected under different electronic resonance conditions using highly fluorescent samples highlight the fluorescence rejection capabilities of FSRS. Data are also presented illustrating our ability: (i) To obtain spectra when there is a large transient absorption change by using a shifted excitation difference technique and (ii) to obtain high time resolution vibrational spectra of transient electronic states.
Collapse
Affiliation(s)
- David W McCamant
- Department of Chemistry, University of California, Berkeley, California 94720
| | | | | | | |
Collapse
|
17
|
McCamant DW, Kukura P, Mathies RA. Femtosecond broadband stimulated Raman: a new approach for high-performance vibrational spectroscopy. APPLIED SPECTROSCOPY 2003; 57:1317-23. [PMID: 14658143 PMCID: PMC1475739 DOI: 10.1366/000370203322554455] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Femtosecond stimulated Raman spectroscopy (FSRS) is a new technique that produces high-quality vibrational spectra free from background fluorescence. FSRS combines a narrow-bandwidth picosecond Raman pump pulse with an approximately 80 fs continuum probe pulse to produce stimulated Raman spectra from the pump-induced gain in the probe spectrum. The high intensity of the Raman pump combined with the broad bandwidth of the probe produces high signal-to-noise vibrational spectra with very short data acquisition times. FSRS spectra of standard solutions and solvents such as aqueous Na2SO4, aqueous KNO3, methanol, isopropanol, and cyclohexane are collected in seconds. Furthermore, stimulated Raman spectra can be obtained using just a single pump-probe pulse pair that illuminates the sample for only approximately 1 ps. Fluorescence rejection is demonstrated by collecting FSRS spectra of dyes (rhodamine 6G, chlorophyll a, and DTTCI) with varying degrees of fluorescence background and resonance enhancement. The high signal-to-noise, short data acquisition time, fluorescence rejection, and high spectral and temporal resolution of femtosecond stimulated Raman spectroscopy make it a valuable new vibrational spectroscopic technique.
Collapse
Affiliation(s)
- David W McCamant
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | | |
Collapse
|
18
|
Eads DD, Moser C, Blackwood ME, Lin CY, Dutton L, Spiro TG. Selective enhancement of resonance Raman spectra of separate bacteriopheophytins in Rb. sphaeroides reaction centers. Biopolymers 2000; 57:64-76. [PMID: 10766957 DOI: 10.1002/(sici)1097-0282(2000)57:2<64::aid-bip3>3.0.co;2-a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tunable dye laser excitation of carefully prepared samples of Rb. sphaeroides reaction centers provides richly detailed resonance Raman (RR) spectra of the bacteriopheophytins, H, and the accessory bacteriochlorophylls, B. These spectra demonstrate selective enhancement of the separate bacteriopheophytins on the active (H(L)) and inactive (H(M)) sides of the reaction centers. The spectra are assigned with the aid of normal coordinate analyses using force fields previously developed for porphyrins and reduced porphyrins. Comparison of the H(L) and H(M) vibrational mode frequencies reveals evidence for greater polarization of the acetyl substituent in H(L) than H(M). This polarization is expected to make H(L) easier to reduce, thereby contributing to the directionality of electron transfer from the special pair, P. In addition, the acetyl polarization of H(L) is increased at low temperature (100 K), helping to account for the increase in electron transfer rate. The polarizing field is suggested to arise from the Mg(2+) of the neighboring accessory bacteriochlorophyll, which is 4.9 A from the acetyl O atom. The 100 K spectra show sharpening and intensification of a number of RR bands, suggesting a narrowing of the conformational distribution of chromophores, which is consistent with the reported narrowing of the distribution in electron transfer rates. Excitation at 800 nm produces high-quality RR spectra of the accessory bacteriochlorophylls, and the spectral pattern is unaltered on tuning the excitation to 810 nm in resonance with the upper exciton transition of P. Either the resonance enhancement of P is weak, or the bacteriochlorophyll RR spectra are indistinguishable for P and B.
Collapse
Affiliation(s)
- D D Eads
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
| | | | | | | | | | | |
Collapse
|
19
|
Lipski RJ, Unger E, Schweitzer-Stenner R. Polarized Resonance Raman Spectroscopy Reveals Two Different Conformers of Metallo(II)octamethylchlorins in CS2. J Phys Chem B 1999. [DOI: 10.1021/jp9918858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Robert J. Lipski
- Institute of Experimental Physics, University of Bremen, PO. Box 330440, 28334 Bremen, Germany, and Department of Chemistry, University of Puerto Rico, Rio Pedras Campus, PO. Box 23346, San Juan, PR 00931-3346
| | - Esko Unger
- Institute of Experimental Physics, University of Bremen, PO. Box 330440, 28334 Bremen, Germany, and Department of Chemistry, University of Puerto Rico, Rio Pedras Campus, PO. Box 23346, San Juan, PR 00931-3346
| | - Reinhard Schweitzer-Stenner
- Institute of Experimental Physics, University of Bremen, PO. Box 330440, 28334 Bremen, Germany, and Department of Chemistry, University of Puerto Rico, Rio Pedras Campus, PO. Box 23346, San Juan, PR 00931-3346
| |
Collapse
|
20
|
Stewart DH, Cua A, Bocian DF, Brudvig GW. Selective Raman Scattering from the Core Chlorophylls in Photosystem I via Preresonant Near-Infrared Excitation. J Phys Chem B 1999. [DOI: 10.1021/jp984409a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David H. Stewart
- Department of Chemistry, Sterling Chemistry Laboratory, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Agnes Cua
- Department of Chemistry, Sterling Chemistry Laboratory, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - David F. Bocian
- Department of Chemistry, Sterling Chemistry Laboratory, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Gary W. Brudvig
- Department of Chemistry, Sterling Chemistry Laboratory, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, and Department of Chemistry, University of California, Riverside, California 92521-0403
| |
Collapse
|