Hexoctahedron in a Nanoframe: Tailoring Stationary and Open Nanogaps for Single-Particle Surface-Enhanced Raman...

Area of Science:

• Plasmonics and Nanotechnology
• Spectroscopy

Background:

• Plasmonic nanostructures with sharp features and nanogaps are crucial for surface-enhanced Raman scattering (SERS) due to localized electromagnetic field enhancement (hot spots).
• Achieving stable, well-defined nanogaps within single nanostructures remains a challenge for optimizing SERS performance.

Purpose of the Study:

• To develop a novel synthetic route for creating gold hexoctahedron-in-a-nanoframe structures (Au HIAFs).
• To investigate the SERS performance of Au HIAFs, leveraging both sharp-feature and nanogap enhancement.
• To demonstrate the potential of Au HIAFs as reusable substrates for sensitive analyte detection.

Main Methods:

• Synthesis of Au hexoctahedron-in-a-nanoframe structures (Au HIAFs) by integrating Au hexoctahedral nanocrystal cores into nanoframe corners without linkers.
• Characterization of the nanostructure morphology and evaluation of electromagnetic field enhancement at sharp features and nanogaps.
• Assessment of SERS performance using various analyte molecules at the single-particle level.

Main Results:

• Successfully synthesized Au HIAFs with stationary, open nanogaps at sharp features.
• Au HIAFs exhibited prominent SERS performance due to the synergistic effect of sharp-feature and gap-enhanced electromagnetic fields.
• Demonstrated single-particle level SERS detection with high sensitivity and reversibility, indicating substrate reusability.

Conclusions:

• Au HIAFs offer a promising platform for SERS by effectively utilizing localized electromagnetic fields.
• The linker-free, stable nanogaps in Au HIAFs enable sensitive and repeatable detection of analytes.
• These findings highlight the potential of Au HIAFs as practical and reusable substrates for advanced SERS applications.