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1
Content available remote

Energy Transfer in Peridinin-Chlorophyll-Protein-Metallic Nanoparticle Hybrid Nanostructure: Effect of Spatial Arrangement

100%
Schmidt M., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
307-311
EN
We theoretically investigate dynamics of excitation in a hybrid nanostructure comprising a photosynthetic complex peridinin-chlorophyll-protein (PCP) coupled to a gold spherical nanoparticle. Our model includes the analytical description of radiative and non-radiative relaxation channels of the chlorophylls in PCP, as well as the change of energy transfer rate within the PCP due to the presence of metal scatterer. We show that by measuring the intensity of fluorescence from selectively excited chlorophyll molecules in the PCP complex, elementary geometric properties of the system can be deduced.
2
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Bioconjugation of Silver Nanowires with Photosynthetic Light-Harvesting Complexes

81%
Olejnik M., Twardowska M., Zaleszczyk W., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
357-364
EN
We demonstrate a way to conjugate a light-harvesting complex, peridinin-chlorophyll-protein, with silver nanowires using biotin-streptavidin linker. In the case of conjugated structure we observe slight increase of the fluorescence intensity of the chlorophyll emission followed by the gradual decrease of the intensity due to photobleaching. For a non-conjugated mixture of peridinin-chlorophyll-protein with silver nanowires only the photobleaching takes place. The results suggest a possible way to fabricate hybrid nanostructures comprising light-harvesting complexes and metallic nanoparticles for achieving the efficient plasmon-induced enhancement of absorption of the light-harvesting complexes.
3
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Gold Nanoparticles with Elongated Shapes: Synthesis and Optical Properties

71%
Olejnik M., Agarwal A., Zaleszczyk W., Kotov N., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
346-349
EN
We use a seed-mediated growth to fabricate gold nanorods in water solution. By changing the amount of silver salt we demonstrate the control of aspect ratio of the obtained rods. The microscopic and spectroscopic analyses provide ways to characterize the morphology and the optical properties of the gold nanorods. Nanorods synthesized using this approach feature length of the order of 50-60 nm, which translates into longitudinal plasmon resonances in the near infrared spectrum region.
4
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Dynamics of Protein Elements of Hybrid Nanostructures - Molecular Dynamics Simulations of Light Harvesting Peridinin-Chlorophyll a-Protein Model

71%
Jasiński A., Mikulska K., Krajnik B., Mackowski S., Nowak W.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
284-288
EN
Hybrid nanostructures are often composed of inorganic parts and "biological" ones. Optimized through million years of evolution light harvesting proteins are hard to mimic synthetically. Promising strategy in search for efficient solar cells is an attachment of selected natural protein systems to inorganic quantum dots. Such experimental hybrid structures should have improved charge separation properties. Among the most promising proteins is peridinin-chlorophyll-protein from Amphidinium carterae (PCP). It has a wide absorption spectrum (420-550 nm), optimized for sunlight. The dynamics of this protein, used in modern nanotechnology has been not addressed yet. In this work we present results of PCP computer modeling using a well established molecular dynamics methodology. The CHARMM27 force field parameters were prepared for this protein and all chromophore components. The system was embedded in a box of water, with proper counter ions, and a number of 10 ns molecular dynamics simulations were run using the NAMD code. It has been found that peridinine chromophores exhibit substantial orientational flexibility but a pair Per612 and Per613 is more rigid than the remaining two carotenoids. Orientation and dynamics of absorption and emission electric dipole moments have been also analyzed. Apparently, the architecture of PCP is not optimized for efficient Per-Chl a energy transfer by the Förster mechanism. Several practical issues related to molecular dynamics simulation of similar hybrid nanostructures are discussed.
5
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Fluorescence Microscopy of Corrole-Single Silver Nanowire Hybrid Nanostructures

61%
Czechowski N., Olejnik M., Nowak-Król A., Piątkowski D., Heiss W., Gryko D., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
333-336
EN
We report on confocal microscopy imaging of hybrid nanostructures composed of silver nanowires and corroles. Both nanomaterials were separated by a 30 nm thick SiO_2 spacer in order to inhibit fluorescence quenching. The results show that for such a hybrid nanostructure the average enhancement of the fluorescence intensity reached 2.5. Importantly, the coupling to plasmon excitations in metallic nanowires leaves no effect on the fluorescence spectrum of the organic molecules.
6
Content available remote

Fluorescence Mapping of PCP Light-Harvesting Complexes Coupled to Silver Nanowires

61%
Krajnik B., Piatkowski D., Olejnik M., Czechowski N., Hofmann E., Heiss W., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
259-262
EN
In this work we demonstrate confocal fluorescence imaging of hybrid nanostructures composed of silver nanowires and peridinin-chlorophyll-protein light-harvesting complexes. The length of silver nanowires, which reaches 10 μm, allows for determination of the nanowire position and consequently direct correlation with the fluorescence image. In this way we probe the influence of plasmon induced electromagnetic field on the fluorescence of light-harvesting complexes. When the nanowires are spaced from the light-harvesting complexes by a 10 nm thick dielectric layer, we observe a fluorescence enhancement, which depends upon the laser excitation wavelength. The measured enhancement values are 2.5 and 1.9 for 405 nm and 485 nm, respectively. Larger enhancement for the 405 nm excitation is attributed to direct creation of plasmon excitations in the silver nanowires.
7
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Influence of Plasmon Resonance in Silver Island Film on the Optical Properties of Peridinin-Chlorophyll-Protein Light-Harvesting Complexes

61%
Ciszak K., Olejnik M., Strzelecki J., Krajnik B., Piątkowski D., Hofmann E., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
275-278
EN
We study the effect of plasmon excitations in silver island film on the optical properties of peridinin-chlorophyll-protein light-harvesting complex using scanning fluorescence microscopy. With this technique we can unambiguously locate areas where the biomolecules are deposited on the metallic nanostructures from the areas where they stick to the glass surface. The enhancement factor of fluorescence intensity obtained for such a hybrid nanostructure is found to be 3. Plasmon excitations in the SIF layer also influence the dynamics of the emission, but in this case the interpretation of the results is more complex.
8
Content available remote

Spectral Dependence of Fluorescence Enhancement in LH2-Au Nanoparticle Hybrid Nanostructures

52%
Bujak L., Brotosudarmo T., Czechowski N., Olejnik M., Ciszak K., Litvin R., Cogdell R., Heiss W., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
252-254
EN
We report on the influence of plasmon resonance in spherical gold nanoparticles on the optical properties of light-harvesting complex LH2 from the purple bacteria Rhodopseudomonas palustris. Systematic studies as a function of the excitation energy and the separation distance indicate that metal enhanced fluorescence shows strong dependence upon both of these parameters. We observe substantial increase of the fluorescence from LH2 complex in a hybrid nanostructure with 12 nm silica spacer. On the other hand, the enhancement measured with laser tuned into the plasmon resonance is almost threefold compared to the off-resonance configuration. The enhancement of fluorescence intensity originates in both cases from the increase of carotenoid absorption in the LH2 complex.
9
Content available remote

Plasmon Enhancement of Fluorescence in Single Light-Harvesting Complexes from em Amphidinium carterae

42%
Bujak Ł., Piątkowski D., Mackowski S., Wörmke S., Jung C., Bräuchle C., Agarwal A., Kotov N., Schulte T., Hofmann E., Brotosudarmo T., Scheer H., Govorov A., Hiller R.
Acta Physica Polonica A
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2009
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vol. 116
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issue S
S-22-S-25
EN
We show that single peridinin-chlorophyll a-protein light-harvesting complexes from dinoflagellate Amphidinium carterae placed near to silver nanoparticles show strongly enhanced fluorescence emission. Single molecule spectroscopy experiments performed at room temperature point toward an enhancement of more than an order of magnitude for optimal conditions. Irrespective of the enhancement, we observe no effect of the metal nanoparticle on the fluorescence emission energy of the complex. This result provides a way to control the optical properties of biomolecules via plasmon excitations in metal nanoparticles.
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