The Experts below are selected from a list of 24447 Experts worldwide ranked by ideXlab platform
Samy Merabia - One of the best experts on this subject based on the ideXlab platform.
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Threshold for Vapor Nanobubble Generation Around Plasmonic Nanoparticles
Journal of Physical Chemistry C, 2017Co-Authors: Julien Lombard, Thierry Biben, Samy MerabiaAbstract:Vapor nanobubbles are transient bubbles that are generated by Plasmonic Nanoparticles illuminated by a pulsed laser and that have been proposed for cancer therapy. Their physical properties are, however, poorly understood. In this article, we discuss the conditions of appearance of these nanobubbles, on the basis of a hydrodynamics phase field model. In particular, we critically assess the role of the Laplace pressure which was invoked to control the onset of nanobubble production. We clearly demonstrate that capillary effects have only a mild effect on the process of nanoscale vaporization. We also characterize the threshold of nanoscale boiling under different conditions of nanoparticle size and contact angle. We conclude that a very thin shell of liquid water should be brought at the spinodal temperature Tspin ≃ 550 K, which gives upper bounds for the shell assumption of Katayama et al. ( Langmuir 2014, 30, 9504), who consider that a finite volume should be heated at Tspin to create a nanobubble. The existence of a finite thermal resistance at the interface between the particle and water controls the vaporization kinetics, and severly delays vapor nanobubble generation in the vicinity of the corresponding threshold. Finally, we compare the predictions of the hydrodynamic model to available experimental data, corresponding to respectively nanoseconds and femtoseconds pulses. The hydrodynamic simulations are in good agreement with the experimental results of Siems et al. ( New J. Phys. 2011, 13, 043018) and Katayama et al., provided that the possibility of gold nanoparticle melting is taken into account. All these considerations help in building a simple thermal diffusive model that may reproduce both the threshold and the kinetics of nanobubble generation, depending on the nanoparticle size and the laser pulse duration, without any fitting parameter.
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threshold for vapor nanobubble generation around Plasmonic Nanoparticles
Journal of Physical Chemistry C, 2017Co-Authors: Julie Lombard, Thierry Ibe, Samy MerabiaAbstract:Vapor nanobubbles are transient bubbles that are generated by Plasmonic Nanoparticles illuminated by a pulsed laser and that have been proposed for cancer therapy. Their physical properties are, however, poorly understood. In this article, we discuss the conditions of appearance of these nanobubbles, on the basis of a hydrodynamics phase field model. In particular, we critically assess the role of the Laplace pressure which was invoked to control the onset of nanobubble production. We clearly demonstrate that capillary effects have only a mild effect on the process of nanoscale vaporization. We also characterize the threshold of nanoscale boiling under different conditions of nanoparticle size and contact angle. We conclude that a very thin shell of liquid water should be brought at the spinodal temperature Tspin ≃ 550 K, which gives upper bounds for the shell assumption of Katayama et al. (Langmuir 2014, 30, 9504), who consider that a finite volume should be heated at Tspin to create a nanobubble. The ex...
Péter Dombi - One of the best experts on this subject based on the ideXlab platform.
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Near-Field-Induced Femtosecond Breakdown of Plasmonic Nanoparticles
Plasmonics, 2019Co-Authors: Benedek J. Nagy, Joachim R. Krenn, Z. Pápa, Laszlo Peter, Christine Prietl, Péter DombiAbstract:We studied the evolution of femtosecond breakdown in lithographically produced Plasmonic Nanoparticles with increasing laser intensity. Localized plasmons were generated with 40-fs laser pulses with up to 1.4 × 10^12 W/cm^2 peak intensity. The damage morphology shows substantial variation with intensity, starting with the detachment of hot spots and stochastic nanoparticle removal. For higher intensities, we observe precise nanolithographic mapping of near-field distributions via ablation. The common feature of these phenomena is the central role played by the single Plasmonic hot spot of the triangular Nanoparticles used. We also derive a damage threshold value from stochastic damage trends on the arrays fostering the optimization of novel nanoarchitectures for nonlinear Plasmonics.
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Heat-Assisted Femtosecond Breakdown of Plasmonic Nanoparticles
2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO Europe-EQEC), 2019Co-Authors: Benedek J. Nagy, Joachim R. Krenn, Z. Pápa, Laszlo Peter, Christine Prietl, Péter DombiAbstract:Metal nanostructures are central to a wide range of ultrafast Plasmonic effects, such as high harmonic generation [1], photoelectron spectroscopy for sub-nm field probing [2], carrier-envelope phase detection [3], plasmon-plasmon coupling [4] etc., where high-intensity ultrafast lasers are used. In any of these cases, a detailed understanding of the laser-induced breakdown of the nanostructures is crucial. Therefore, we systematically investigate the femtosecond pulse-induced breakdown of Plasmonic Nanoparticles with a few-cycle, state-of-the-art laser source.
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Ultrafast strong-field photoemission from Plasmonic Nanoparticles.
Nano Letters, 2013Co-Authors: Péter Dombi, Anton Hörl, Péter Rácz, István Márton, Andreas Trügler, Joachim R. Krenn, Ulrich HohenesterAbstract:We demonstrate the ultrafast generation of electrons from tailored metallic Nanoparticles and unravel the role of Plasmonic field enhancement in this process by comparing resonant and off-resonant particles, as well as different particle geometries. We find that electrons become strongly accelerated within the evanescent fields of the Plasmonic Nanoparticles and escape along straight trajectories with orientations governed by the particle geometry. These results establish Plasmonic Nanoparticles as versatile ultrafast, nanoscopic sources of electrons.
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Ultrafast strong-field photoemission from Plasmonic Nanoparticles
2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE IQEC, 2013Co-Authors: Péter Dombi, Anton Hörl, Péter Rácz, István Márton, Andreas Trügler, Joachim R. Krenn, Ulrich HohenesterAbstract:We demonstrate strong-field photoemission from Plasmonic Nanoparticles by ultrashort pulses. Significant (x110) field enhancement attributed to surface plasmons enable 25-eV electron generation in nano-localized fields around Nanoparticles. Correlation between Plasmonic resonance and electron spectra is shown.
Joachim R. Krenn - One of the best experts on this subject based on the ideXlab platform.
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Near-Field-Induced Femtosecond Breakdown of Plasmonic Nanoparticles
Plasmonics, 2019Co-Authors: Benedek J. Nagy, Joachim R. Krenn, Z. Pápa, Laszlo Peter, Christine Prietl, Péter DombiAbstract:We studied the evolution of femtosecond breakdown in lithographically produced Plasmonic Nanoparticles with increasing laser intensity. Localized plasmons were generated with 40-fs laser pulses with up to 1.4 × 10^12 W/cm^2 peak intensity. The damage morphology shows substantial variation with intensity, starting with the detachment of hot spots and stochastic nanoparticle removal. For higher intensities, we observe precise nanolithographic mapping of near-field distributions via ablation. The common feature of these phenomena is the central role played by the single Plasmonic hot spot of the triangular Nanoparticles used. We also derive a damage threshold value from stochastic damage trends on the arrays fostering the optimization of novel nanoarchitectures for nonlinear Plasmonics.
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Heat-Assisted Femtosecond Breakdown of Plasmonic Nanoparticles
2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO Europe-EQEC), 2019Co-Authors: Benedek J. Nagy, Joachim R. Krenn, Z. Pápa, Laszlo Peter, Christine Prietl, Péter DombiAbstract:Metal nanostructures are central to a wide range of ultrafast Plasmonic effects, such as high harmonic generation [1], photoelectron spectroscopy for sub-nm field probing [2], carrier-envelope phase detection [3], plasmon-plasmon coupling [4] etc., where high-intensity ultrafast lasers are used. In any of these cases, a detailed understanding of the laser-induced breakdown of the nanostructures is crucial. Therefore, we systematically investigate the femtosecond pulse-induced breakdown of Plasmonic Nanoparticles with a few-cycle, state-of-the-art laser source.
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Ultrafast strong-field photoemission from Plasmonic Nanoparticles.
Nano Letters, 2013Co-Authors: Péter Dombi, Anton Hörl, Péter Rácz, István Márton, Andreas Trügler, Joachim R. Krenn, Ulrich HohenesterAbstract:We demonstrate the ultrafast generation of electrons from tailored metallic Nanoparticles and unravel the role of Plasmonic field enhancement in this process by comparing resonant and off-resonant particles, as well as different particle geometries. We find that electrons become strongly accelerated within the evanescent fields of the Plasmonic Nanoparticles and escape along straight trajectories with orientations governed by the particle geometry. These results establish Plasmonic Nanoparticles as versatile ultrafast, nanoscopic sources of electrons.
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Ultrafast strong-field photoemission from Plasmonic Nanoparticles
2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE IQEC, 2013Co-Authors: Péter Dombi, Anton Hörl, Péter Rácz, István Márton, Andreas Trügler, Joachim R. Krenn, Ulrich HohenesterAbstract:We demonstrate strong-field photoemission from Plasmonic Nanoparticles by ultrashort pulses. Significant (x110) field enhancement attributed to surface plasmons enable 25-eV electron generation in nano-localized fields around Nanoparticles. Correlation between Plasmonic resonance and electron spectra is shown.
Luis M Lizmarzan - One of the best experts on this subject based on the ideXlab platform.
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modern applications of Plasmonic Nanoparticles from energy to health
Advanced Optical Materials, 2015Co-Authors: Dorleta Jimenez De Aberasturi, Ana B Serranomontes, Luis M LizmarzanAbstract:NanoPlasmonics is a rapidly growing field of research that opens up multiple opportunities toward practical applications. The understanding of the extreme confinement of light at the nanoscale has facilitated the development of a wide range of interesting materials for many different fields. Nanoparticles of noble metals, such as gold or silver, present unique optical properties that may end up making a large impact on our daily lives. Modern biomedical techniques can successfully treat cancer via plasmon-mediated photothermal therapy, in which metal nanoprobes act as intense heaters to kill cancer cells. Moreover, our society is also seeing an increasing interest in the development of alternative (green) energy sources, where Plasmonic nanostructures are also considered to provide an advantage, e.g., improving the performance and feasibility of photovoltaic devices. In this progress report, relevant advances and applications of Plasmonic Nanoparticles, from energy to health, are discussed, and their potential implications in future society are highlighted.
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optical sensing of biological chemical and ionic species through aggregation of Plasmonic Nanoparticles
Journal of Materials Chemistry C, 2014Co-Authors: Lakshminarayana Polavarapu, Jorge Perezjuste, Luis M LizmarzanAbstract:Plasmonic Nanoparticles made of gold and silver have attracted a great deal of research attention in various fields, such as biosensors, imaging, therapy, nanophotonics, catalysis and light harvesting due to their unique optical and electronic properties. Plasmonic nanoparticle colloids may exhibit strong colours in the visible region due to localized surface plasmon resonances, whereas their aggregates exhibit different linear and nonlinear optical properties. Therefore, a smart design of chemical interactions between analytes and the Nanoparticles surface may lead to gradual optical changes, which can be probed by various sensing methods, allowing quantitative analyte detection. A significant amount of research has been carried out toward the development of Plasmonic sensors based on analyte-induced aggregation of Au or Ag Nanoparticles, and the sensitivity and selectivity of such Plasmonic biosensors have been greatly improved over the years. In this feature article, we summarize different design strategies that have been employed to induce the aggregation of Plasmonic Nanoparticles upon the addition of various analytes such as DNA, proteins, organic molecules and inorganic ions. We introduce various optical assays, such as colorimetry, surface-enhanced Raman scattering, two-photon photoluminescence, dynamic light scattering, hyper-Rayleigh scattering and chiroptical activity. From the discussion, it can be concluded that Plasmonic sensors based on nanoparticle aggregation offer simple, highly sensitive and selective detection of various analytes. Finally, we discuss some of the future directions of Plasmonic nanosensors toward device integration for practical applications.
Julien Lombard - One of the best experts on this subject based on the ideXlab platform.
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Threshold for Vapor Nanobubble Generation Around Plasmonic Nanoparticles
Journal of Physical Chemistry C, 2017Co-Authors: Julien Lombard, Thierry Biben, Samy MerabiaAbstract:Vapor nanobubbles are transient bubbles that are generated by Plasmonic Nanoparticles illuminated by a pulsed laser and that have been proposed for cancer therapy. Their physical properties are, however, poorly understood. In this article, we discuss the conditions of appearance of these nanobubbles, on the basis of a hydrodynamics phase field model. In particular, we critically assess the role of the Laplace pressure which was invoked to control the onset of nanobubble production. We clearly demonstrate that capillary effects have only a mild effect on the process of nanoscale vaporization. We also characterize the threshold of nanoscale boiling under different conditions of nanoparticle size and contact angle. We conclude that a very thin shell of liquid water should be brought at the spinodal temperature Tspin ≃ 550 K, which gives upper bounds for the shell assumption of Katayama et al. ( Langmuir 2014, 30, 9504), who consider that a finite volume should be heated at Tspin to create a nanobubble. The existence of a finite thermal resistance at the interface between the particle and water controls the vaporization kinetics, and severly delays vapor nanobubble generation in the vicinity of the corresponding threshold. Finally, we compare the predictions of the hydrodynamic model to available experimental data, corresponding to respectively nanoseconds and femtoseconds pulses. The hydrodynamic simulations are in good agreement with the experimental results of Siems et al. ( New J. Phys. 2011, 13, 043018) and Katayama et al., provided that the possibility of gold nanoparticle melting is taken into account. All these considerations help in building a simple thermal diffusive model that may reproduce both the threshold and the kinetics of nanobubble generation, depending on the nanoparticle size and the laser pulse duration, without any fitting parameter.