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).

Metallic Nanostructures as Localized Plasmon Resonance Enhanced Scattering Probes for Multiplex Dark Field Targeted Imaging of Cancer Cells.

Abstract: In this paper, we report the use of bioconjugated gold nanorods and silver nanoparticles as targeted localized surface plasmon resonance enhanced scattering probes for dark-field multiplex and transmission electron microscopy (TEM) imaging of pancreatic cancer cells. We take advantage of the spectrally widely separated localized plasmon resonance of the gold nanorods and silver nanoparticles which produce wavelength selective plasmon resonance scattering to allow multiplex imaging with high contrast. When the surfaces are functionalized, aqueous dispersions of bioconjugated gold nanorods and silver nanoparticles are prepared. We demonstrate receptor-mediated delivery of bioconjugated gold nanorods and silver nanoparticles simultaneously into pancreatic cancer cells, using multiplexed dark-field microscopy technique. We also show that the bioconjugated metallic nanostructures can be used for high-contrast TEM imaging as well.

Enhancement of band gap emission stimulated by defect loss.

Abstract: Defect radiation has been always considered as the most important loss for an emitter based on band gap emission. Here, we propose a novel approach which goes against this conventional wisdom. Based on the resonance effect between the surface plasmon of metal nanoparticles and defect emission, it is possible to convert the useless defect radiation to the useful excitonic emission with a giant enhancement factor. Through the transfer of the energetic electrons excited by surface plasmon from metal nanoparticles to the conduction band of the emitter, the band gap emission can be greatly enhanced, while the defect emission can be suppressed to noise level.

Self‐Assembled SERS Substrates with Tunable Surface Plasmon Resonances

Abstract: The fabrication of surface-enhanced Raman spectroscopy (SERS) substrates that are optimized for use with specific laser wavelength–analyte combinations is addressed. In order to achieve large signal enhancement, temporal stability, and reproducibility over large substrate areas at low cost, only self-assembly and templating processes are employed. The resulting substrates consist of arrays of gold nanospheres with controlled diameter and spacing, properties that dictate the optical response of the structure. Tunability of the extended surface plasmon resonance is observed in the range of 520–1000 nm. It is demonstrated that the enhancement factor is maximized when the surface plasmon resonance is red-shifted with respect to the SERS instrument laser line. Despite relying on self-organization, site-to-site enhancement factor variations smaller than 10% are obtained.

Resonance Energy Transfer-Promoted Photothermal and Photodynamic Performance of Gold-Copper Sulfide Yolk-Shell Nanoparticles for Chemophototherapy of Cancer.

Abstract: Gold (Au) core@void@copper sulfide (CuS) shell (Au–CuS) yolk–shell nanoparticles (YSNPs) were prepared in the present study for potential chemo-, photothermal, and photodynamic combination therapy, so-called “chemophototherapy”. The resonance energy transfer (RET) process was utilized in Au–CuS YSNPs to achieve both enhanced photothermal and photodynamic performance compared with those of CuS hollow nanoparticles (HNPs). A series of Au nanomaterials as cores that had different localized surface plasmon resonance (LSPR) absorption peaks at 520, 700, 808, 860, and 980 nm were embedded in CuS HNPs to screen the most effective Au–CuS YSNPs according to the RET process. Thermoresponsive polymer was fabricated on these YSNPs’ surface to allow for controlled drug release. Au808–CuS and Au980–CuS YSNPs were found capable of inducing the largest temperature elevation and producing the most significant hydroxyl radicals under 808 and 980 nm laser irradiation, respectively, which could accordingly cause the most sev...

Surface Plasmon-Coupled Emission with Gold Films

Abstract: In a recent report we demonstrated efficient collection of emission by coupling to surface plasmons on a thin silver film, resulting in a directional signal in the glass substrate. We call the phenomenon surface plasmon coupled emission (SPCE). In the present report we examined sulforhodamine 101 (S101) in thin polymer films on 50 nm thick gold films on glass. We observed efficient SPCE through thin gold films. This result was surprising because metallic gold is typically an efficient quencher of fluorescence. The energy effectively coupled through the gold film into the glass at a sharply defined angle, but somewhat less sharp than for a comparable silver film. About 50% of the total emission appeared as SPCE, irrespective of direct excitation or excitation via the plasmon resonance evanescent wave. The emission was p-polarized with different wavelengths appearing at different angles. The lifetime of S101 was mostly unaffected by the gold film. These results indicate that SPCE occurs over long distances, larger than for quenching by energy transfer to the gold. We conclude highly efficient detection devices can be constructed by using fluorophores on gold-coated surfaces.