Silicon Microchannel-Driven Raman Scattering Enhancement to Improve Gold Nanorod Functions as a SERS Substrate toward...

Area of Science:

• Nanotechnology
• Spectroscopy
• Materials Science

Background:

• Surface-enhanced Raman scattering (SERS) relies on substrates to amplify Raman signals.
• Developing reliable and high-performance SERS substrates is crucial for sensitive molecular detection.
• Gold nanorods (AuNRs) are effective plasmonic nanomaterials for SERS applications.

Purpose of the Study:

• To investigate shape-induced enhanced Raman scattering (SIERS) using V-shaped silicon microchannels.
• To enhance the performance of gold nanorods (AuNRs) as SERS substrates.
• To achieve ultra-low concentration detection with high sensitivity and reproducibility.

Main Methods:

• Fabrication of V-shaped silicon microchannels.
• Preparation and characterization of gold nanorod (AuNR) aggregates.
• Utilizing scattered electric field simulations to analyze electromagnetic field distribution.
• Experimental Raman spectroscopy measurements on V-shaped and flat substrates.

Main Results:

• Bare V-shaped silicon substrates showed a 4.29-fold increase in Raman signal intensity compared to flat substrates due to SIERS.
• The combination of V-shaped microchannels and AuNR aggregates enabled "trap" effects for molecule confinement.
• Attomolar (10^-18 mol L^-1) detection limits were achieved with high reproducibility (silhouette coefficient of 0.83).

Conclusions:

• V-shaped microchannels combined with AuNRs create highly sensitive and reproducible SERS substrates.
• SIERS effects and geometric design contribute to enhanced electromagnetic field distribution and molecule confinement.
• This approach offers a promising platform for ultra-sensitive detection in various analytical applications.