Physically Reshaped Silver Microplates Formed Monolayer Assemblies at Air/Water Interface as High-Performance SERS...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Surface-enhanced Raman scattering (SERS) offers high sensitivity for chemical analysis.
• Fabricating high-performance SERS substrates often involves complex and costly methods.
• A balance between SERS performance and ease of fabrication is crucial for practical applications.

Purpose of the Study:

• To develop a facile and scalable strategy for preparing high-performance SERS substrates.
• To combine top-down and bottom-up fabrication concepts for creating silver microplate monolayers.
• To investigate the SERS capabilities of the fabricated substrate.

Main Methods:

• Fabrication of uniform silver microplates (~93.5 nm thickness, 3.33 µm lateral size) using mechanical ball-milling.
• Spontaneous interfacial self-assembly of silver microplates into a continuous monolayer film at the air/water interface.
• Transfer of the silver microplate monolayer onto a plasma-treated silicon wafer to form the SERS substrate.

Main Results:

• The resulting SERS substrate displayed a porous, network-like structure with densely packed microplates.
• High density of electromagnetic hot spots was generated at the nanogaps between microplates.
• A SERS detection limit of 1 nM for Rhodamine 6G was achieved with good spatial uniformity (RSD ~9.94%).

Conclusions:

• A cost-effective and scalable self-assembly route for fabricating high-performance SERS substrates from physically reshaped silver microplates was established.
• The developed method overcomes the typical trade-off between SERS performance and fabrication simplicity.
• This approach holds promise for advancing ultrasensitive chemical analysis.