Graphene/Ag nanoholes composites for quantitative surface-enhanced Raman scattering

Area of Science:

• Nanotechnology
• Spectroscopy
• Materials Science

Background:

• Quantitative analysis in Surface-Enhanced Raman Scattering (SERS) is crucial but hindered by substrate performance fluctuations.
• Achieving reliable and reproducible SERS results requires advanced substrate design and analytical methods.

Purpose of the Study:

• To develop a robust quantitative SERS method overcoming substrate variability.
• To establish an internal standard approach for accurate SERS measurements.
• To demonstrate the efficacy of graphene/Ag nanoholes as SERS substrates for quantification.

Main Methods:

• Fabrication of silver nanoholes using surface plasmon (SP) lithography.
• Transfer of a monolayer graphene film onto the silver nanoholes structure.
• Utilizing the graphene 2D Raman peak as an internal standard for normalizing analyte signals.

Main Results:

• The graphene/Ag nanoholes (GE/AgNHs) structure served as a stable SERS substrate.
• Normalization using the graphene internal standard reduced relative standard deviation (RSD) from 25% to 12%.
• Successful quantification of rhodamine 6G (R6G) down to a detection limit of 10^-15 M was achieved.

Conclusions:

• The internal standard method with graphene/Ag nanoholes provides a reliable quantitative SERS approach.
• This method significantly improves the accuracy and reproducibility of SERS measurements.
• The developed technique enables highly sensitive detection and quantification of analytes.