Probing innovative microfabricated substrates for their reproducible SERS activity

Area of Science:

• Nanotechnology
• Spectroscopy
• Materials Science

Background:

• Surface-enhanced Raman spectroscopy (SERS) relies on plasmonic nanostructures to amplify weak molecular signals.
• Conventional SERS substrates often use nanoparticle arrays, which may not fully exploit plasmonic enhancement mechanisms.

Purpose of the Study:

• To introduce novel microfabricated SERS substrates with sharp-edged nanostructures.
• To investigate the fabrication and SERS activity of gold nanostar and nanodiamond arrays.
• To achieve higher enhancement factors utilizing the lightning rod effect.

Main Methods:

• Fabrication of SERS substrates using electron beam lithography and ion beam etching.
• Preparation of gold nanostar arrays via a one-stage process.
• Preparation of gold nanodiamond arrays via a two-stage process.
• Testing SERS activity using a crystal violet monolayer.

Main Results:

• Achieved highly reproducible SERS substrates with arrays of sharp-edged nanostructures.
• Demonstrated significant SERS enhancement factors: at least 130 for nanodiamond arrays and 310 for nanostar arrays.
• Validated the effectiveness of the lightning rod effect in sharp nanostructures.

Conclusions:

• The developed microfabricated nanostar and nanodiamond arrays are promising SERS-active substrates.
• Sharp-edged nanostructures offer superior SERS performance compared to conventional dots.
• The fabrication methods ensure reproducibility for practical applications in chemical sensing.