Electron energy-loss spectroscopy of surface plasmon activity in wrinkled gold structures

Abstract

The surface plasmon response of a cross-sectional segment of a wrinkled gold film is studied using electron energy loss spectroscopy (EELS). EELS data demonstrate that wrinkled gold structures act as a suitable substrate for surface plasmons to propagate. The intense surface variations in these structures facilitate the resonance of a wide range of surface plasmons, leading to the broadband surface plasmon response of these geometries from the near-infrared to visible wavelengths. The metallic nanoparticle boundary element method toolbox is used to simulate plasmon eigenmodes in these structures. Eigenmode simulations show how the diverse morphology of the wrinkled structure leads to its high spectral complexity. Micron-sized structural features that do not provide interactions between segments of the wrinkle have only a small effect on the surface plasmon resonance response, whereas nanofeatures strongly affect the resonant modes of the geometry. According to eigenmode calculations, different eigenenergy shifts around the sharp folds contribute to the broadband response and infrared activity of these structures; these geometrical features also support higher energy (shorter wavelength) symmetric and anti-symmetric plasmon coupling across the two sides of the folds. It is also shown that additional plasmon eigenstates are introduced from hybridization of modes across nanogaps between structural features in close proximity to each other. All of these factors contribute to the broadband response of the wrinkled gold structures.

Graft-Then-Shrink: Simultaneous Generation of Antifouling Polymeric Interfaces and Localized Surface Plasmon Resonance Biosensors

“…16 The shrinking process can simultaneously produce LSPR sensors by first depositing a thin film of Au or other plasmonic materials onto the shrinkable substrate. Upon shrinking, the Au layer forms LSPR-active micro-and nanowrinkles 17 that are exploited here to detect protein interactions by tracking changes in visible-light absorbance using a standard plate reader. This represents the first descriptions of substrate shrinking to improve the fouling properties of polymer coatings as well as of Au wrinkled LSPR sensors for the detection of protein interactions.…”

Alignment-invariant signal reality reconstruction in hyperspectral imaging using a deep convolutional neural network architecture

“…photonics, biosensing, imaging, and plasmon-mediated therapies 22,[25][26][27][28][29][30][31] . Thus, any improvement in the EELS technique has a direct impact on fields such as nanoscale electronic and photonic structures.…”