Gold-Deposited Graphene Nanosheets for Self-Cleaning Graphene Surface-Enhanced Raman Spectroscopy with Superior...

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Graphene-metal interactions induce chemical enhancements crucial for sensing applications.
• Surface-enhanced Raman spectroscopy (SERS) relies on plasmonic nanostructures for signal amplification.
• Optimizing metal nanoparticle deposition on graphene is key to maximizing SERS performance.

Purpose of the Study:

• To explore gold nanoparticle-decorated graphene nanosheets for enhanced Raman spectroscopy.
• To investigate the charge-transfer effects and SERS capabilities of metal-doped graphene (G-SERS).
• To evaluate the potential of this composite material as a photocatalyst.

Main Methods:

• Systematic optimization of gold (Au) nanoparticle thickness sputtered onto graphene nanosheets.
• Characterization of graphene Raman spectra and photoluminescence (PL) quenching.
• Evaluation of SERS signal enhancement factors and limit of detection for methylene blue (MB) and 2,6-pyridinedicarboxylic acid (DPA).

Main Results:

• Au decoration induced n-type doping in graphene, confirmed by Raman spectra and PL quenching.
• Achieved significant Raman intensity enhancement factors of ~10^8 (MB) and 10^7 (DPA).
• Demonstrated ultra-low detection limits down to 10^-16 M (MB) and 10^-11 M (DPA) with high signal stability.
• Showcased effective photocatalytic degradation of MB dye (~94.4%) within 60 minutes.

Conclusions:

• Controlled gold decoration on graphene nanosheets enhances SERS performance through combined charge-transfer and electromagnetic effects.
• The G-SERS platform offers superior sensitivity, consistency, and stability for sensing applications.
• The developed material shows promise as an efficient photocatalyst for dye degradation.