A silver nanoparticle embedded hydrogel as a substrate for surface contamination analysis by surface-enhanced Raman...

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Traditional surface-enhanced Raman scattering (SERS) substrates often struggle with conforming to rough or varied material surfaces.
• Existing SERS methods can be limited in their ability to extract and analyze trace organic species from complex substrates.

Purpose of the Study:

• To fabricate a novel, adaptable SERS substrate capable of analyzing organic species on diverse material surfaces.
• To evaluate the substrate's performance in terms of sensitivity and detection limits for various contaminants.

Main Methods:

• Fabrication of a SERS substrate using silver nanoparticles (Ag NPs) encapsulated within a poly(vinyl alcohol) (PVA) hydrogel, termed PVA "slime".
• Application of the PVA slime SERS substrate to analyze surfaces of varying roughness (sandpaper, cotton, metal, wood) contaminated with nile blue A (NBA).
• Detection of other organic compounds, including pesticides and Sudan red III, on glass surfaces.

Main Results:

• The PVA slime SERS substrate demonstrated excellent viscoelasticity, enabling conformal contact with arbitrary surface roughness.
• Achieved low limits of detection (LOD) for NBA down to 100 ppb (0.79 ng/∼3 cm²) across all tested materials.
• Successfully detected pesticides and Sudan red III on glass surfaces with an LOD of 1.6 ng/∼3 cm².

Conclusions:

• The developed PVA slime SERS substrate offers a versatile and effective platform for trace organic species detection on challenging surfaces.
• This innovative SERS substrate overcomes limitations of traditional methods, showing promise for contaminant analysis and material inspection.