Surface-enhanced fluorescence imaging on linear arrays of plasmonic half-shells

Area of Science:

• Plasmonics and Photonics
• Colloidal Crystals
• Surface-Enhanced Fluorescence (SEF)

Background:

• Hybrid colloidal photonic-plasmonic crystals offer unique optical properties.
• Linear arrays of silver half-shells (LASHSs) are a novel platform for SEF studies.
• Understanding SEF enhancement distribution is crucial for optimizing substrate design.

Purpose of the Study:

• To investigate Surface-Enhanced Fluorescence (SEF) intensity and lifetime on LASHSs.
• To identify and map the specific locations of SEF effects.
• To correlate SEF enhancements with topographical features and electromagnetic field distribution.

Main Methods:

• Surface-Enhanced Fluorescence (SEF) imaging (intensity and lifetime).
• Scanning confocal fluorescence imaging and optical microscopy.
• Rayleigh scattering imaging and finite difference time domain (FDTD) simulations.

Main Results:

• SEF effects, including intensity increase and lifetime decrease, were localized.
• Optimal SEF enhancement occurs at the junctions/crevices between adjacent silver half-shells.
• Simulated field maps confirmed high electromagnetic field enhancement and strong emitter-plasmon interactions at these locations.

Conclusions:

• Detailed knowledge of SEF enhancement distribution relative to topography is established.
• This provides a basis for rational design of efficiency-optimized SEF substrates.
• LASHSs represent a versatile platform for applications in optoelectronics, sensing, and anti-counterfeiting.