Spatially multiplexed dark-field microspectrophotometry for nanoplasmonics

Area of Science:

• Nanotechnology
• Optics
• Materials Science

Background:

• Understanding light-matter interactions at the nanoscale is crucial.
• Substrate effects significantly influence the local surface plasmon resonance (LSPR) of metallic nanoparticles.
• High-throughput techniques with high spatial and spectral resolution are needed for LSPR analysis.

Purpose of the Study:

• To introduce a novel technique, Spatially Multiplexed Micro-Spectrophotometry (SMMS), for analyzing light-matter interactions at the nanoscale.
• To demonstrate the capability of SMMS for polarization-resolved spectral and spatial analysis of scattered light from metallic nanoparticles.
• To showcase SMMS's application in assessing substrate effects on LSPR and characterizing nanoparticles.

Main Methods:

• Development and application of Spatially Multiplexed Micro-Spectrophotometry (SMMS).
• Performing polarization-resolved dark-field spectral analysis of gold nanoparticles on a silicon surface.
• Mapping spatial distribution of scattered light intensity with 40 nm lateral resolution over 0.02 mm(2) areas.

Main Results:

• SMMS achieves spectroscopic analysis three orders of magnitude faster than conventional methods.
• The technique maps LSPR shifts and scattering pattern changes due to substrate effects on single nanoparticles and dimers.
• Rapid discrimination and counting of nanoparticle monomers and dimers, with 1 nm accuracy for individual nanoparticle diameter assessment.

Conclusions:

• SMMS is a powerful, high-throughput technique for nanoscale optical analysis.
• It provides significant insights into substrate-mediated LSPR phenomena.
• SMMS enables rapid and accurate characterization of metallic nanoparticles, including size and aggregation state.