Self-Assembled Three-Dimensional Polyamide/Silver Nanoparticle Pore Array as a Highly Sensitive and Reproducible SERS...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Surface-enhanced Raman scattering (SERS) requires highly sensitive substrates.
• Developing robust and reproducible SERS substrates is crucial for chemical sensing.
• Polyamide (PA) pore arrays offer a versatile platform for nanomaterial assembly.

Purpose of the Study:

• To self-assemble silver nanoparticles (AgNPs) onto PA pore arrays to create optimized 3D SERS substrates.
• To investigate the optimal conditions for PA/Ag 3D pore array substrate fabrication.
• To evaluate the SERS performance for detecting model molecules and environmental contaminants.

Main Methods:

• Self-assembly of AgNPs onto PA pore arrays via hydrogen bonding.
• Optimization of substrate parameters: pore depth, AgNP size, pH, and assembly time.
• SERS performance evaluation using rhodamine 6G (R6G) as a probe molecule.
• Label-free detection of the pesticide diquat.

Main Results:

• Optimized PA/Ag 3D pore array substrate achieved with 500 nm pore depth, 30 nm AgNPs, pH 5.0, and 24 h assembly time.
• SERS detection limit for R6G reached 10^-13 M with <20% relative standard deviation.
• Label-free detection of diquat achieved with a detection limit of 2.69 × 10^-9 M.
• Substrate demonstrated good enhancement ability and reproducibility.

Conclusions:

• The developed 3D SERS substrate exhibits excellent sensitivity and reproducibility.
• The optimized substrate meets environmental monitoring requirements for drinking water.
• This 3D SERS substrate holds significant potential for contaminant detection and chemical sensing applications.