Lateral Size Effect of Graphene Oxide on Its Surface-Enhanced Raman Scattering Property

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Graphene oxide (GO) is a promising material for surface-enhanced Raman scattering (SERS) due to its unique properties.
• The influence of GO's lateral size on its SERS performance has not been systematically explored.

Purpose of the Study:

• To investigate the effect of graphene oxide's lateral size on its SERS capabilities.
• To determine if larger GO sheets offer improved SERS performance compared to smaller ones.

Main Methods:

• Size-fractionalization of as-synthesized GO into large-sized GO (LGO) and small-sized GO (SGO) using centrifugation and membrane filtration.
• Immobilization of size-fractionalized GO sheets on a substrate for SERS analysis.
• Hybridization of GO sheets with plasmonic silver nanoparticles to assess SERS enhancement.

Main Results:

• Large-sized GO (LGO) demonstrated significantly higher SERS activity than small-sized GO (SGO) when tested with rhodamine 6G and crystal violet.
• The positive correlation between GO lateral size and SERS enhancement was consistent, even when hybridized with silver nanoparticles.
• Quantitative analysis confirmed that LGO provides a superior enhancement factor compared to SGO and as-synthesized GO (AGO).

Conclusions:

• The lateral size of graphene oxide plays a crucial role in its SERS performance.
• Large-sized GO is a more effective platform for SERS applications than smaller GO sheets.
• These findings provide valuable insights for optimizing GO-based SERS substrates.