Surface plasmon resonance

About: Surface plasmon resonance is a research topic. Over the lifetime, 24909 publications have been published within this topic receiving 810976 citations. The topic is also known as: Surface plasmon resonance & SPR (technology).

Silver Nanoplates with Special Shapes: Controlled Synthesis and Their Surface Plasmon Resonance and Surface-Enhanced Raman Scattering Properties

Abstract: Shape-controlled synthesis of metal nanostructures has opened many new possibilities to design ideal building blocks for future nanodevices. In this work, new types of monodisperse silver nanoplates with complex shapes, namely, a disklike shape and flowerlike shapes, were controllably synthesized in high yield by reducing [Ag(NH3)2]+ with ascorbic acid in the presence of silver seed at room temperature. Unlike previous methods for synthesizing the silver nanoplates in the presence of cetyltrimethylammonium bromide (CTAB) micelles, the use of the precursor [Ag(NH3)2]+, other than Ag+, provides a flexible strategy to control the procession of the reduction reaction in a mild way. These silver nanoplates with shapes of disk and flower were shown to possess surface plasmon resonance (SPR) that directly relates to their geometric shapes. As a result of their high anisotropy in shape, the flowerlike silver nanoplates exhibit excellent surface-enhanced Raman scattering (SERS) enhancement ability relative to sphe...

Preparation of Au-BiVO4 heterogeneous nanostructures as highly efficient visible-light photocatalysts.

Abstract: Au-BiVO4 heterogeneous nanostructures have been successfully prepared through in situ growth of gold nanoparticles on BiVO4 microtubes and nanosheets via a cysteine-linking strategy. The experimental results reveal that these Au-BiVO4 heterogeneous nanostructures exhibit much higher visible-light photocatalytic activities than the individual BiVO4 microtubes and nanosheets for both dye degradation and water oxidation. The enhanced photocatalytic efficiencies are attributed to the charge transfer from BiVO4 to the attached gold nanoparticles as well as their surface plasmon resonance (SPR) absorption. These new heteronanostructures are expected to show considerable potential applications in solar-driven wastewater treatment and water splitting.

Plasmon modes of nanosphere trimers and quadrumers.

Abstract: Using the plasmon hybridization method, we investigate the plasmon frequencies and optical absorption spectra of symmetric configurations of nanosphere trimers and quadrumers. Plasmon hybridization allows us to express the fundamental plasmon modes of these multinanosphere systems as linear combinations of the plasmons of individual nanospheres in a manner analogous to molecular orbital theory. We show how group theory may be used to interpret the plasmon modes of each multiparticle system as specific structure-dependent symmetric combinations of the plasmon modes of the individual nanoparticles. We compare the optical absorption spectra calculated using plasmon hybridization with the spectra obtained using finite difference time domain simulations.

Nanoparticles for photoacoustic imaging

Abstract: Nanoparticles have been designed and applied as contrast enhancers in various optical imaging techniques, such as optical coherence tomography, fluorescence imaging, and optical reflectance microscopy. As an emerging hybrid imaging modality, photoacoustic imaging (PAI) has also benefited from the application of these nanoparticle-based contrast agents. We review this rapidly growing field and describe the applications of nanoparticles in PAI. Particular focus is given to nanoparticles whose absorption mechanism is based on surface plasmon resonance, including gold nanoshells, nanorods, and nanocages. Dye-embedded nanoparticles are also reviewed. Specifically, the design and application of each nanoparticle-based contrast agent in relation to the field of PAI are detailed.

Gold nanoshells on polystyrene cores for control of surface plasmon resonance.

Abstract: A method is presented for synthesizing core-shell structures consisting of monodisperse polystyrene latex nanospheres as cores and gold nanoparticles as shells. Use of polystyrene spheres as the core in these structures is advantageous because they are readily available commercially in a wide range of sizes, and with dyes or other molecules doped into them. Gold nanoparticles, ranging in size from 1 to 20 nm, are prepared by reduction of a gold precursor with sodium citrate or tetrakis(hydroxymethyl)phosphonium chloride (THPC). Carboxylate-terminated polystyrene spheres are functionalized with 2-aminoethanethiol hydrochloride (AET), which forms a peptide bond with carboxylic acid groups on their surface, resulting in a thiol-terminated surface. Gold nanoparticles then bind to the thiol groups to provide up to about 50% coverage of the surface. These nanoparticles serve as seeds for growth of a continuous gold shell by reduction of additional gold precursor. The shell thickness and roughness can be controlled by the size of the nanoparticle seeds as well as by the process of their growth into a continuous shell. By variation of the relative sizes of the latex core and the thickness of the gold overlayer, the plasmon resonance of the nanoshell can be tuned to specific wavelengths across the visible and infrared range of the electromagnetic spectrum, for applications ranging from the construction of photonic crystals to biophotonics. The position and width of the plasmon resonance extinction peak are well-predicted by extended Mie scattering theory.