Highly stable gelatin layer-protected gold nanoparticles as surface-enhanced Raman scattering substrates

Area of Science:

• Nanotechnology
• Materials Science
• Spectroscopy

Background:

• Gold nanoparticles (AuNPs) are crucial for surface-enhanced Raman scattering (SERS) due to their plasmonic properties.
• Developing stable, well-defined AuNPs with functional groups is essential for advanced SERS applications.
• Gelatin, a biopolymer rich in amine and carboxylic groups, presents a potential green alternative for nanoparticle synthesis.

Purpose of the Study:

• To synthesize highly stable gold nanoparticles using gelatin as a reducing and stabilizing agent.
• To evaluate the suitability of these gelatin-protected gold nanoparticles as substrates for SERS.
• To characterize the functional groups present on the synthesized nanoparticles for potential further modifications.

Main Methods:

• Synthesis of gold nanoparticles using gelatin as a reducing and stabilizing agent.
• Transmission Electron Microscopy (TEM) for size and monodispersity determination.
• Fourier-Transform Infrared Spectroscopy (FT-IR) for surface functional group analysis.
• SERS measurements using Rhodamine 6G and Ruthenium bipyridine as reporter molecules.

Main Results:

• Formation of highly stable, monodisperse 13 nm gold nanoparticles.
• SERS activity was demonstrated using Rhodamine 6G and Ruthenium bipyridine.
• FT-IR confirmed the presence of amine and carboxylic acid groups on the nanoparticle surface.
• Nanoparticle size was largely independent of initial gelatin concentration.

Conclusions:

• Gelatin is an effective agent for producing stable, monodisperse gold nanoparticles suitable for SERS.
• The presence of amine and carboxylic groups allows for further bioconjugation.
• This green synthesis method yields versatile gold nanoparticles with excellent solubility and stability for SERS applications.