Raspberry-Like Plasmonic Nanoaggregates with Programmable Hierarchical Structures for Reproducible SERS Detection of...

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Materials Science

Background:

• Conventional solid and liquid surface-enhanced Raman spectroscopy (SERS) substrates suffer from inconsistent sample distribution, aggregation, and precipitation, leading to signal irreproducibility.
• Developing stable and sensitive SERS substrates is crucial for accurate trace chemical detection.

Purpose of the Study:

• To design and synthesize novel, colloidally stable, raspberry-like plasmonic nanoaggregates for SERS applications.
• To overcome the limitations of existing SERS substrates by creating a high-density hotspot platform.

Main Methods:

• Fabrication of raspberry-like nanoaggregates using functionalized polystyrene (PS) microspheres as templates for Au@Ag core-shell nanoparticle self-assembly.
• Characterization of nanoaggregate stability and SERS performance.
• Testing SERS detection limits for various analytes including rhodamine 6G (R6G), malachite green (MG), adenine, and uracil.

Main Results:

• Successfully synthesized stable, raspberry-like plasmonic nanoaggregates within 5 minutes.
• Achieved high sensitivity for SERS detection of R6G (1 × 10^-10 M), MG (1 × 10^-16 M), adenine (3 × 10^-8 M), and uracil (3 × 10^-7 M).
• Demonstrated successful trace detection of adenine in clinical urine samples.

Conclusions:

• The developed raspberry-like nanoaggregates offer a reproducible and stable SERS substrate solution.
• This modular assembly approach advances SERS substrate design and trace-chemical detection technologies.