Functionalized core-shell Ag@TiO₂ nanoparticles for enhanced Raman spectroscopy: a sensitive detection method for...

Area of Science:

• Nanomaterials Science
• Spectroscopy
• Surface Chemistry

Background:

• Surface plasmon resonance (SPR) is crucial for enhancing Raman signals.
• Core-shell nanoparticles offer unique optical and chemical properties.
• Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) enables sensitive detection of analytes on various surfaces.

Purpose of the Study:

• To demonstrate the efficacy of core-shell Ag@TiO2 nanoparticles in SHINERS experiments.
• To investigate the tunability of Raman signals using different excitation wavelengths.
• To compare the performance of Ag@TiO2-based SHINERS with traditional SERS.

Main Methods:

• Synthesis of core-shell Ag@TiO2 nanoparticles.
• Grafting of a copper(II) complex onto the Ag@TiO2 surface.
• Raman spectroscopy measurements using multiple excitation wavelengths (514, 633, and 785 nm).
• Estimation of enhancement factors for the SHINERS assembly.

Main Results:

• The Ag@TiO2 core-shell structure effectively supported SHINERS experiments.
• Raman signals of the copper(II) complex were successfully tuned by varying excitation wavelengths.
• Significant enhancement factors were achieved with the Ag@TiO2 SHINERS assembly.
• Grafting onto Ag@TiO2 showed advantages over Ag@SiO2 for this application.

Conclusions:

• Core-shell Ag@TiO2 nanoparticles are highly effective for SHINERS applications.
• The Ag@TiO2 platform provides tunable and enhanced Raman signal detection.
• This approach offers a promising alternative to traditional SERS for complex sample analysis.