Tunable surface-enhanced Raman scattering from high-density gold semishell arrays with controllable dimensions

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman scattering (SERS) requires substrates with specific nanostructures to amplify weak signals.
• Existing fabrication methods for SERS substrates can be complex, costly, or difficult to scale.
• Developing reproducible and large-area SERS substrates is crucial for practical applications.

Purpose of the Study:

• To report a convenient and reproducible technique for fabricating large-area gold semishell arrays.
• To demonstrate the utility of these arrays as robust and cost-efficient SERS substrates.
• To explore the tunability of the surface structure for optimizing SERS enhancement.

Main Methods:

• Fabrication of porous anodic alumina (PAA) stamps.
• Mechanical pressing of PAA stamps into gold/polymer bilayer structures.
• Characterization of the resulting gold semishell arrays.
• Finite-difference time-domain (FDTD) calculations to predict SERS performance.

Main Results:

• Successful fabrication of large-area gold semishell arrays.
• Demonstrated potential of the arrays as cost-efficient and robust SERS substrates.
• Tunable surface structure achieved by varying PAA fabrication parameters and imprinting pressures.
• FDTD calculations predicted excellent SERS characteristics due to high hot spot density.

Conclusions:

• The reported technique offers a scalable and reproducible method for producing high-performance SERS substrates.
• The fabricated gold semishell arrays exhibit tunable properties for optimized SERS enhancement.
• The nanostructure's design shows promise for sensitive and reliable chemical detection via SERS.