LSPR – Inorganic Nanoparticles Group http://www.inorganicnanoparticles.net Research group at ICN Mon, 13 Jan 2020 13:55:52 +0000 en-US hourly 1 https://wordpress.org/?v=4.7.28 Hollow metal nanostructures for enhanced plasmonics: synthesis, local plasmonic properties and applications. Published in Nanophotonics http://www.inorganicnanoparticles.net/nanophotonics/ Fri, 28 Sep 2018 10:09:28 +0000 http://www.inorganicnanoparticles.net/?p=2118 Metallic nanostructures have received great attention due to their ability to generate surface plasmon resonances, which are collective oscillations of conduction electrons of a material excited by an electromagnetic wave. Plasmonic metal nanostructures are able to localize and manipulate the light at the nanoscale and, therefore, are attractive building blocks for various emerging applications. In particular, hollow nanostructures are promising plasmonic materials as cavities are known to have better plasmonic properties than their solid counterparts thanks to the plasmon hybridization mechanism. The hybridization of the plasmons results in the enhancement of the plasmon fields along with more homogeneous distribution as well as the reduction of localized surface plasmon resonance (LSPR) quenching due to absorption. In this review, we summarize the efforts on the synthesis of hollow metal nanostructures with an emphasis on the galvanic replacement reaction. In the second part of this review, we discuss the advancements on the characterization of plasmonic properties of hollow nanostructures, covering the single nanoparticle experiments, nanoscale characterization via electron energy-loss spectroscopy and modeling and simulation studies. Examples of the applications, i.e. sensing, surface enhanced Raman spectroscopy, photothermal ablation therapy of cancer, drug delivery or catalysis among others, where hollow nanostructures perform better than their solid counterparts, are also evaluated.

Hollow metal nanostructures for enhanced plasmonics: synthesis, local plasmonic properties and applications.

]]> New Paper on the Study of the Localized Multipolar Surface Plasmon Resonances of Silver Nanoparticles Published in Langmuir. http://www.inorganicnanoparticles.net/new-paper-on-the-study-of-the-localized-multipolar-surface-plasmon-resonances-of-silver-nanoparticles-published-in-langmuir/ Fri, 10 Mar 2017 19:33:43 +0000 http://www.inorganicnanoparticles.net/?p=1977 Silver nanoparticles absorb and scatter light with extraordinary efficiency due to the collective oscillations of the conduction electrons of the metal surface when they are excited by light of an specific wavelengths. These oscillations, known as a localized surface plasmon resonances (LSPRs) are determined by the size, shape and local environment in which the nanoparticle is embedded. In this work, we have spectroscopically investigated the effect of the size and surface coating on the sensitivity of localized multipolar surface plasmon resonances in high-quality silver colloidal solutions with precisely controlled sizes from 10 to 220 nm and well-defined surface chemistry, identifying the size-dependence of dipolar, quadrupolar and octapolar modes. Besides, we studied how these multipolar resonances are affected by modifications of the NP’ surface coating, in particular the dependences on the length and the anchor group of the molecule attached at its surface, revealing the higher sensitivity of larger sizes, dipolar than higher-order modes, thiol than amine groups, and long than short molecules. We also extend this study to gold nanoparticles, aiming to compare the sensitivity of both materials, quantifying the higher sensitivity of silver. The work has now been published in Langmuir under the title “Quantifying the Sensitivity of Multipolar (Dipolar, Quadrupolar and Octapolar) Surface Plasmon Resonances in Silver Nanoparticles: The Effect of Size, Composition and Surface Coating.”

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