Plasmon-Controlled Light-Harvesting: Design Rules for Biohybrid Devices via Multiscale Modeling

Nano Letters ◽  
2013 ◽  
Vol 13 (9) ◽  
pp. 4475-4484 ◽  
Author(s):  
Oliviero Andreussi ◽  
Alessandro Biancardi ◽  
Stefano Corni ◽  
Benedetta Mennucci
Keyword(s):  
Multiscale Modeling ◽  
Light Harvesting ◽  
Design Rules

scholarly journals The molecular mechanisms of light adaption in light-harvesting complexes of purple bacteria revealed by a multiscale modeling

2019 ◽  
Vol 10 (42) ◽  
pp. 9650-9662 ◽  
Author(s):  
Felipe Cardoso Ramos ◽  
Michele Nottoli ◽  
Lorenzo Cupellini ◽  
Benedetta Mennucci
Keyword(s):  
Multiscale Modeling ◽  
Molecular Mechanisms ◽  
Light Harvesting ◽  
Purple Bacteria ◽  
Spectral Tuning ◽  
Light Harvesting Complexes

The spectral tuning of LH2 antenna complexes arises from H-bonding, acetyl torsion, and inter-chromophore couplings.

scholarly journals Multiscale modeling of molecular structure and optical properties of complex supramolecular aggregates

2020 ◽  
Vol 11 (42) ◽  
pp. 11514-11524 ◽  
Author(s):  
Anna S. Bondarenko ◽  
Ilias Patmanidis ◽  
Riccardo Alessandri ◽  
Paulo C. T. Souza ◽  
Thomas L. C. Jansen ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Optical Properties ◽  
Multiscale Modeling ◽  
Light Harvesting ◽  
Photophysical Properties ◽  
Light Harvesting Complex ◽  
Supramolecular Aggregates ◽  
Microscopic Origin

Multiscale modeling resolves the molecular structure of a synthetic light-harvesting complex, unraveling the microscopic origin of its photophysical properties.

scholarly journals An All-Optical Excitonic Switch Templated on a DNA Scaffold Operated in the Liquid and Solid Phases

2020 ◽  
Author(s):  
Donald L. Kellis
Keyword(s):  
Self Assembly ◽  
Light Harvesting ◽  
Dna Nanotechnology ◽  
Building Blocks ◽  
Optically Active ◽  
Electronic Circuits ◽  
Design Rules ◽  
All Optical ◽  
Solid Phases ◽  
Liquid And Solid Phases

The natural excitonic circuitry of photosynthetic organisms, including light harvesting antennas, provides a distinctive example of a highly attractive bio-inspired alternative to electronic circuits. Excitonics, which capitalizes on spatially arranged optically active molecules ability to capture and transfer light energy below the diffraction limit of light has garnered recognition as a potential disruptive replacement for electronic circuits. However, assembly of optically active molecules to construct even simple excitonic devices has been impeded by the limited maturity of suitable molecular scale assembly technologies. An example of nanophotonic circuitry, natural light harvesting antennas employ proteins as scaffolds to organize and self-assemble light-active molecules into excitonic networks capable of capturing and converting light to excitonic energy, and transferring that energy at ambient temperature. Protein self-assembly is extremely complex due to the over 20 amino acids building blocks used in the self-assembly process and the difficulty of predicting how proteins actually fold. An alternative method for organization and self-assembly may be found in the field DNA nanotechnology. DNA nanotechnology provides the most viable means to organize optically active molecules as there are only four nucleic acid building blocks and well-established simple design rules. Leveraging DNA nanotechnology will meet the requirements of precise proximity (selectivity) and appropriate number (specificity) needed to create larger arrays of multifunctional optically active molecules. Employing the design rules of DNA self-assembly, we have designed, engineered and operated an all-optical excitonic switch consisting of donor and acceptor chromophores and diarylethene photochromic modulating units assembled with nanometer scale precision. This work demonstrates the first integration of three diarylethene photochromic units into a single DNA oligonucleotide. Photoisomerization of diarylethenes has been shown to be one of the fastest photochemical reactions thereby affording potential switching speeds in the 10's of picoseconds. Adopting diarylethenes as optically reversible switching units provided the ability to operate the all-optical excitonic switch through nearly 200 cycles without overt cyclic fatigue and excellent ON/OFF stability in both the liquid and solid phases. Assessing the static and dynamic cycling behavior of the all-optical excitonic switch allowed for the development of a model to predict characteristic switching times (τ) of 17.0 and 23.3 seconds for the liquid and solid phases, respectively which align well with the experimental data thereby validating the model. While these times are much faster than that of other non-optically based DNA-templated excitonic switches (τ ~ 10's of minutes), the times noted here are limited by the steady-state optical instrumentation, (i.e., photon flux, detector integration time, and slit cycling speed), used to characterize the all-optical excitonic switches. Our model predicts switching times in the picosecond range could be achieved with the use of a high peak power ultrafast laser. First-order calculations estimate the all-optical excitonic switch has a footprint 37X smaller, a smaller volume by over 3 orders of magnitude and over an order of magnitude less energy per cycle than a state-of-the-art MOSFET. These findings, combined with no production of waste products and the potential ability to switch at speeds in the 10's of picoseconds, establishes a prospective pathway toward all-optical excitonic circuits.

Plasmon Enhanced Light Harvesting: Multiscale Modeling of the FMO Protein Coupled with Gold Nanoparticles

2014 ◽  
Vol 119 (21) ◽  
pp. 5197-5206 ◽  
Author(s):  
Oliviero Andreussi ◽  
Stefano Caprasecca ◽  
Lorenzo Cupellini ◽  
Ingrid Guarnetti-Prandi ◽  
Ciro A. Guido ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Multiscale Modeling ◽  
Light Harvesting ◽  
Fmo Protein

High-Resolution electron crystallography of the light-harvesting chlorophyll-a/b protein complex from chloroplast membranes

1990 ◽  
Vol 48 (1) ◽  
pp. 610-610
Author(s):  
Werner Kühlbrandt ◽  
Da Neng Wang ◽  
K.H. Downing
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Chlorophyll A ◽  
Protein Complex ◽  
Structural Integrity ◽  
Light Harvesting ◽  
Lhc Ii ◽  
Diffraction Patterns ◽  
Difference Fourier ◽  
2D Crystals

The light-harvesting chlorophyll-a/b protein complex (LHC-II) is the most abundant membrane protein in the chloroplasts of green plants where it functions as a molecular antenna of solar energy for photosynthesis. We have grown two-dimensional (2d) crystals of the purified, detergent-solubilized LHC-II . The crystals which measured 5 to 10 μm in diameter were stabilized for electron microscopy by washing with a 0.5% solution of tannin. Electron diffraction patterns of untilted 2d crystals cooled to 130 K showed sharp spots to 3.1 Å resolution. Spot-scan images of 2d crystals were recorded at 160 K with the Berkeley microscope . Images of untilted crystals were processed, using the unbending procedure by Henderson et al . A projection map of the complex at 3.7Å resolution was generated from electron diffraction amplitudes and high-resolution phases obtained by image processing .A difference Fourier analysis with the same image phases and electron diffraction amplitudes recorded of frozen, hydrated specimens showed no significant differences in the 3.7Å projection map. Our tannin treatment therefore does not affect the structural integrity of the complex.

Macroorganisation and flexibility of thylakoid membranes

2019 ◽  
Vol 476 (20) ◽  
pp. 2981-3018 ◽  
Author(s):  
Petar H. Lambrev ◽  
Parveen Akhtar
Keyword(s):  
Light Harvesting ◽  
Current Knowledge ◽  
Three Dimensional ◽  
Photosynthetic Apparatus ◽  
Dynamic Responses ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Light Harvesting Complex ◽  
Complex Ii ◽  
Light Harvesting Complex Ii

Abstract The light reactions of photosynthesis are hosted and regulated by the chloroplast thylakoid membrane (TM) — the central structural component of the photosynthetic apparatus of plants and algae. The two-dimensional and three-dimensional arrangement of the lipid–protein assemblies, aka macroorganisation, and its dynamic responses to the fluctuating physiological environment, aka flexibility, are the subject of this review. An emphasis is given on the information obtainable by spectroscopic approaches, especially circular dichroism (CD). We briefly summarise the current knowledge of the composition and three-dimensional architecture of the granal TMs in plants and the supramolecular organisation of Photosystem II and light-harvesting complex II therein. We next acquaint the non-specialist reader with the fundamentals of CD spectroscopy, recent advances such as anisotropic CD, and applications for studying the structure and macroorganisation of photosynthetic complexes and membranes. Special attention is given to the structural and functional flexibility of light-harvesting complex II in vitro as revealed by CD and fluorescence spectroscopy. We give an account of the dynamic changes in membrane macroorganisation associated with the light-adaptation of the photosynthetic apparatus and the regulation of the excitation energy flow by state transitions and non-photochemical quenching.

Contrasting underlying mechanisms of different barrier coating types

TAPPI Journal ◽  
2018 ◽  
Vol 17 (01) ◽  
pp. 31-37
Author(s):  
Bryan McCulloch ◽  
John Roper ◽  
Kaitlin Rosen
Keyword(s):  
Food Packaging ◽  
Underlying Mechanism ◽  
Consumer Products ◽  
Mechanical Degradation ◽  
Design Rules ◽  
Barrier Coatings ◽  
Barrier Materials ◽  
Barrier Coating ◽  
Coating Type ◽  
Underlying Mechanisms

Barrier coatings are used in applications including food packaging, dry goods, and consumer products to prevent transport of different compounds either through or into paper and paperboard substrates. These coatings are useful in packaging to contain active ingredients, such as fragrances, or to protect contents from detrimental substances, such as oxygen, water, grease, or other chemicals of concern. They also are used to prevent visual changes or mechanical degradation that might occur if the paper becomes saturated. The performance and underlying mechanism depends on the barrier coating type and, in particular, on whether the barrier coating is designed to prevent diffusive or capillary transport. Estimates on the basis of fundamental transport phenomena and data from a broad screening of different barrier materials can be used to understand the limits of various approaches to construct barrier coatings. These estimates also can be used to create basic design rules for general classes of barrier coatings.

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