Au nanoparticles for SERS: Temperature-controlled nanoparticle morphologies and their Raman enhancing properties

Area of Science:

• Nanotechnology
• Materials Science
• Spectroscopy

Background:

• Gold nanoparticles exhibit localized surface plasmon resonance (LSPR), crucial for enhancing Raman scattering.
• Nanoparticle morphology significantly influences LSPR properties and surface-enhanced Raman scattering (SERS) capabilities.
• Controlling nanoparticle synthesis allows for tailoring surface features to optimize plasmonic enhancement.

Purpose of the Study:

• To synthesize quasi-fractal gold nanoparticles using a modified procedure.
• To investigate the effect of nanoparticle morphology on LSPR and surface-enhancing capabilities.
• To compare the SERS enhancement of quasi-fractal gold nanoparticles with other morphologies.

Main Methods:

• Modified temperature-controlled synthesis of quasi-fractal gold nanoparticles.
• Characterization of nanoparticle morphology and surface features.
• Comparative analysis of SERS enhancement across different gold nanoparticle shapes and concentrations.

Main Results:

• Quasi-fractal gold nanoparticles demonstrate enhanced Raman scattering intensity due to numerous sharp surface features and LSPR.
• In fixed nanoparticle concentration, quasi-fractal nanoparticles yield the highest surface enhancement.
• In fixed gold concentration, spherical nanoparticles provide the largest enhancement.
• Branched features enable coupling with laser wavelengths, offering flexibility beyond single LSPR.

Conclusions:

• Quasi-fractal gold nanoparticles offer significant potential for SERS applications.
• Nanoparticle morphology is a critical factor in optimizing plasmonic enhancement for sensing.
• The tunable LSPR of quasi-fractal nanoparticles facilitates applications requiring laser wavelength flexibility, such as advanced molecular sensing and medical imaging.