Quantum Coherence and its Impact on Biomimetic Light-Harvesting

2014 ◽  
Vol 67 (5) ◽  
pp. 729 ◽  
Author(s):  
Alistair J. Laos ◽  
Paul M. G. Curmi ◽  
Pall Thordarson
Keyword(s):  
Charge Separation ◽  
Quantum Coherence ◽  
Light Harvesting ◽  
Energy Transfer Mechanism ◽  
Energy Research ◽  
Energy Capture ◽  
Photosynthetic Organisms ◽  
Energy Needs ◽  
And Function

The survival of all photosynthetic organisms relies on the initial light harvesting step, and thus, after ~3 billion years of evolution energy capture and transfer has become a highly efficient and effective process. Here we examine the latest developments on understanding light harvesting, particularly in systems that exhibit an ultrafast energy transfer mechanism known as quantum coherence. With increasing knowledge of the structural and function parameters that produce quantum coherence in photosynthetic organisms, we can begin to replicate this process through biomimetic systems providing a faster and more efficient approach to harvesting and storing solar power for the worlds energy needs. Importantly, synthetic systems that display signs of quantum coherence have also been created and the first design principles for synthetic systems utilising quantum coherence are beginning to emerge. Recent claims that quantum coherence also plays a key role in ultrafast charge-separation highlights the importance for chemists, biologists, and material scientists to work more closely together to uncover the role of quantum coherence in photosynthesis and solar energy research.

scholarly journals Quantum coherence controls the charge separation in a prototypical artificial light-harvesting system

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Carlo Andrea Rozzi ◽  
Sarah Maria Falke ◽  
Nicola Spallanzani ◽  
Angel Rubio ◽  
Elisa Molinari ◽  
...  
Keyword(s):  
Charge Separation ◽  
Quantum Coherence ◽  
Light Harvesting ◽  
Artificial Light

scholarly journals Quantum coherence controls the charge separation in a prototypical artificial light harvesting system

2012 ◽  
Author(s):  
Sarah M. Falke ◽  
Carlo Andrea Rozzi ◽  
Nicola Spallanzani ◽  
Angel Rubio ◽  
Elisa Molinari ◽  
...  
Keyword(s):  
Charge Separation ◽  
Quantum Coherence ◽  
Light Harvesting ◽  
Artificial Light

scholarly journals Nature does not rely on long-lived electronic quantum coherence for photosynthetic energy transfer

2017 ◽  
Vol 114 (32) ◽  
pp. 8493-8498 ◽  
Author(s):  
Hong-Guang Duan ◽  
Valentyn I. Prokhorenko ◽  
Richard J. Cogdell ◽  
Khuram Ashraf ◽  
Amy L. Stevens ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Quantum Coherence ◽  
Light Harvesting ◽  
Electronic Excitation Energy ◽  
Light Harvesting Complexes ◽  
Ultrafast Optical ◽  
Ultrafast Optical Spectroscopy ◽  
Biomolecular Complexes ◽  
Orthodox View

During the first steps of photosynthesis, the energy of impinging solar photons is transformed into electronic excitation energy of the light-harvesting biomolecular complexes. The subsequent energy transfer to the reaction center is commonly rationalized in terms of excitons moving on a grid of biomolecular chromophores on typical timescales <100 fs. Today’s understanding of the energy transfer includes the fact that the excitons are delocalized over a few neighboring sites, but the role of quantum coherence is considered as irrelevant for the transfer dynamics because it typically decays within a few tens of femtoseconds. This orthodox picture of incoherent energy transfer between clusters of a few pigments sharing delocalized excitons has been challenged by ultrafast optical spectroscopy experiments with the Fenna–Matthews–Olson protein, in which interference oscillatory signals up to 1.5 ps were reported and interpreted as direct evidence of exceptionally long-lived electronic quantum coherence. Here, we show that the optical 2D photon echo spectra of this complex at ambient temperature in aqueous solution do not provide evidence of any long-lived electronic quantum coherence, but confirm the orthodox view of rapidly decaying electronic quantum coherence on a timescale of 60 fs. Our results can be considered as generic and give no hint that electronic quantum coherence plays any biofunctional role in real photoactive biomolecular complexes. Because in this structurally well-defined protein the distances between bacteriochlorophylls are comparable to those of other light-harvesting complexes, we anticipate that this finding is general and directly applies to even larger photoactive biomolecular complexes.

scholarly journals pH dependence, kinetics and light-harvesting regulation of nonphotochemical quenching inChlamydomonas

2019 ◽  
Vol 116 (17) ◽  
pp. 8320-8325 ◽  
Author(s):  
Lijin Tian ◽  
Wojciech J. Nawrocki ◽  
Xin Liu ◽  
Iryna Polukhina ◽  
Ivo H. M. van Stokkum ◽  
...  
Keyword(s):  
Light Harvesting ◽  
Ph Dependence ◽  
Ph Sensor ◽  
Complex Stress ◽  
Nonphotochemical Quenching ◽  
Ps Ii ◽  
Light Harvesting Complex ◽  
Photosynthetic Organisms

Sunlight drives photosynthesis but can also cause photodamage. To protect themselves, photosynthetic organisms dissipate the excess absorbed energy as heat, in a process known as nonphotochemical quenching (NPQ). In green algae, diatoms, and mosses, NPQ depends on the light-harvesting complex stress-related (LHCSR) proteins. Here we investigated NPQ inChlamydomonas reinhardtiiusing an approach that maintains the cells in a stable quenched state. We show that in the presence of LHCSR3, all of the photosystem (PS) II complexes are quenched and the LHCs are the site of quenching, which occurs at a rate of ∼150 ps−1and is not induced by LHCII aggregation. The effective light-harvesting capacity of PSII decreases upon NPQ, and the NPQ rate is independent of the redox state of the reaction center. Finally, we could measure the pH dependence of NPQ, showing that the luminal pH is always above 5.5 in vivo and highlighting the role of LHCSR3 as an ultrasensitive pH sensor.

Extending the limits of natural photosynthesis and implications for technical light harvesting

2013 ◽  
Vol 17 (01n02) ◽  
pp. 1-15 ◽  
Author(s):  
Min Chen ◽  
Hugo Scheer
Keyword(s):  
Light Harvesting ◽  
Photosynthetic Apparatus ◽  
Oxygenic Photosynthesis ◽  
The Sun ◽  
Photosynthetic Organisms ◽  
Energy Needs ◽  
Production Of Hydrogen ◽  
Primary Reactions ◽  
Life On Earth ◽  
Technical Solutions

Photosynthetic organisms provide, directly or indirectly, the energy that sustains life on earth by harvesting light from the sun. The amount of light impinging on the surface of the earth vastly surpasses the energy needs of life including man. Harvesting the sun is, therefore, an option for a sustainable energy source: directly by improving biomass production, indirectly by coupling it to the production of hydrogen for fuel or, conceptually, by using photosynthetic strategies for technological solutions based on non-biological or hybrid materials. In this review, we summarize the various light climates on earth, the primary reactions responsible for light harvesting and transduction to chemical energy in photosynthesis, and the mechanisms of competitively adapting the photosynthetic apparatus to the ever-changing light conditions. The focus is on oxygenic photosynthesis, its adaptation to the various light-climates by specialized pigments and on the extension of its limits by the evolution of red-shifted chlorophylls. The implications for potential technical solutions are briefly discussed.

scholarly journals Quantum coherence controls the charge separation in a prototypical artificial light harvesting system

2013 ◽  
Vol 41 ◽  
pp. 08017
Author(s):  
S.M. Falke ◽  
C. A. Rozzi ◽  
N. Spallanzani ◽  
A. Rubio ◽  
E. Molinari ◽  
...  
Keyword(s):  
Charge Separation ◽  
Quantum Coherence ◽  
Light Harvesting ◽  
Artificial Light

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

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