A Bioinspired Ag Nanoparticle/PPy Nanobowl/TiO₂ Micropyramid SERS Substrate

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman spectroscopy (SERS) requires advanced substrates for sensitive molecular detection.
• Developing substrates with enhanced optical and chemical properties is crucial for SERS applications.
• Bioinspired structures offer unique advantages for designing functional nanomaterials.

Purpose of the Study:

• To fabricate a novel SERS substrate using a Ag nanoparticle/PPy nanobowl/TiO2 micropyramid structure.
• To investigate the substrate's performance in terms of sensitivity, uniformity, and recyclability.
• To demonstrate the applicability of micropyramid structures in composite SERS materials.

Main Methods:

• Soft imprinting was used to transfer a micropyramid structure onto a TiO2 substrate.
• Polypyrrole (PPy) nanobowls were assembled on the TiO2 micropyramids using a polystyrene (PS) template.
• Silver (Ag) nanoparticles were deposited to form the final Ag/PPy nanobowl/TiO2 micropyramid SERS substrate.

Main Results:

• The fabricated substrate exhibited excellent antireflection properties.
• Ultra-high sensitivity was achieved, detecting R6G molecules down to 10^-9 mol/L.
• A high Raman enhancement factor of 3.4 × 10^5 was recorded.
• The substrate demonstrated excellent uniformity and recyclability due to catalytic degradation performance.

Conclusions:

• The novel Ag/PPy nanobowl/TiO2 micropyramid structure serves as a highly effective SERS substrate.
• The bioinspired compound eye-like structure enhances substrate performance.
• This fabrication method broadens the scope of materials for composite SERS substrates beyond silicon.