High-performance, large-area flexible SERS substrates prepared by reactive ion etching for molecular detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Surface-enhanced Raman scattering (SERS) offers rapid, sensitive, and non-destructive molecular detection.
• Conventional rigid SERS substrates face challenges in cost, large-area fabrication, uniformity, and suitability for curved surfaces.

Purpose of the Study:

• To develop a flexible SERS substrate with enhanced sensitivity, uniformity, and repeatability.
• To address the limitations of rigid SERS substrates for inspecting curved object surfaces.

Main Methods:

• Fabrication of a flexible polydimethylsiloxane (PDMS) substrate.
• Deposition of a SiO2/Ag layer via ion beam sputtering.
• Formation of a densely packed nanostructure using reactive ion etching.
• Deposition of a precious metal layer by thermal evaporation.

Main Results:

• The developed flexible SERS substrate demonstrates high sensitivity and good uniformity/repeatability.
• The nanostructure, optimized through etching, enhances SERS performance.
• Excellent SERS performance was observed for crystalline violet detection, with a limit of detection of 10^-11 M.

Conclusions:

• The novel flexible SERS substrate provides an effective and convenient platform for molecular substance detection.
• This advancement is particularly beneficial for applications requiring inspection of curved surfaces.
• The optimized nanostructure and optical properties contribute to superior SERS capabilities.