Large-Area Nanowire Arrays Achieving Surface Lattice Resonance for Highly Sensitive SERS Applications

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Fabricating large-area surface-enhanced Raman scattering (SERS) substrates with high sensitivity, uniformity, and cost-effectiveness remains a significant challenge.
• Conventional methods struggle to meet the demands of high-throughput production for advanced SERS applications.

Purpose of the Study:

• To present a novel strategy for fabricating large-area periodic nanowire arrays for SERS applications.
• To overcome the limitations of existing SERS substrates through precise control over geometric parameters and material composition.

Main Methods:

• Integration of programmable cyclic deposition with high-precision nanoskiving techniques.
• Fine-tuning of structural dimensions and material composition by controlling stacking sequence and nanoskiving parameters.
• Fabrication of periodic nanowire arrays with adjustable geometric parameters and versatile material compositions.

Main Results:

• Achieved excellent structural integrity, uniform electromagnetic field distribution, and good signal reproducibility (RSD = 1.9%) over ≈206 mm².
• Demonstrated excellent sensitivity with a detection limit as low as 1 × 10⁻¹² M for a target molecule using Ag150-Gap20-Ag150-Gap115-Period435 arrays.
• Excitation of high-quality-factor surface lattice resonances through enhanced coupling efficiency.

Conclusions:

• The presented strategy offers an efficient, scalable, and material-adaptive method for high-throughput fabrication of SERS substrates.
• This approach facilitates the application of SERS in critical areas such as environmental monitoring, food safety, and bioanalysis.
• The developed technique enables precise control over SERS substrate properties, leading to enhanced performance.