Three-Dimensional (3D) Surface-Enhanced Raman Spectroscopy (SERS) Substrates for Sensing Low-Concentration Molecules...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Surface-enhanced Raman spectroscopy (SERS) in liquid solutions faces challenges like signal instability and low sensitivity, especially for trace analytes.
• Existing SERS methods struggle with reproducibility and reliable data acquisition in dynamic liquid environments.

Purpose of the Study:

• To develop a robust and reproducible 3D SERS substrate for enhanced detection in liquid samples.
• To overcome the limitations of traditional SERS techniques in analyzing low-concentration analytes and dynamic processes.

Main Methods:

• Fabrication of a 3D SERS substrate using silica microparticles (SMPs) functionalized with plasmonic nanoparticles (NPs).
• Application of the 3D SERS substrate in liquid solutions, utilizing glycerin for immobilization and high-resolution imaging.
• Conducting time-dependent SERS measurements with freely suspended SMPs in aqueous solutions.

Main Results:

• Achieved enhancement factors (EFs) greater than 200 in both immobilized and suspended 3D SERS configurations.
• Demonstrated reliable and reproducible SERS measurements in liquid environments.
• Enabled sensitive detection of low-abundance analytes.

Conclusions:

• The developed 3D SERS substrate offers a reliable method for liquid-phase analysis, overcoming previous limitations.
• This technique shows significant potential for real-time monitoring, sensitive molecular detection, and applications in biomolecular studies, environmental monitoring, and diagnostics.