Spiked gold beads as substrates for single-particle SERS

Area of Science:

• Nanotechnology
• Plasmonics
• Spectroscopy

Background:

• Smooth nanoparticles enhance Raman signals but lack optical microscopy visibility.
• High aspect ratio gold nanorods are precursors for novel particle morphologies.

Purpose of the Study:

• To engineer and characterize a new family of spiked nanoparticles.
• To evaluate their potential for ultrasensitive optical analysis.

Main Methods:

• Growth of high aspect ratio gold nanorods to form spiked particles.
• Characterization of particle size and morphology.
• Fabrication of thin films with varying particle densities.
• Testing surface-enhanced Raman scattering (SERS) efficiency.

Main Results:

• Spiked particles larger than 300 nm were successfully synthesized.
• These particles sustain localized surface plasmon resonances for Raman signal enhancement.
• Spiked particles are visible under standard confocal optical microscopy.
• SERS efficiency was tested as a function of particle density in thin films.

Conclusions:

• Spiked nanoparticles offer a unique combination of SERS enhancement and optical microscopy detectability.
• Engineered thin films provide a portable platform for in-field ultrasensitive analysis.
• This technology advances capabilities for rapid, sensitive detection.