Tunable shell thickness in analyte-responsive core-shell plasmonic arrays at liquid-liquid interface for dual-mode...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Hydrogen sulfide (H₂S) in water poses significant health risks.
• Allicin (diallyl trisulfide, DATS) is a key marker in garlic products with medicinal properties.
• Direct detection of H₂S and DATS using surface-enhanced Raman scattering (SERS) is challenging due to their low Raman scattering cross-sections.

Purpose of the Study:

• To develop a novel and sensitive method for detecting trace amounts of H₂S and DATS in aqueous environments.
• To leverage surface-enhanced Raman scattering (SERS) with advanced plasmonic nanostructures for enhanced detection sensitivity.
• To provide a practical solution for monitoring H₂S and DATS in real-world water samples.

Main Methods:

• Fabrication of thickness-tunable silver-core/silver-sulfide-shell (Ag@Ag₂S) plasmonic nanostructures.
• Utilizing a liquid-liquid interface (LLI) setup for the plasmonic arrays.
• Investigating the correlation between Ag₂S shell thickness and SERS signal enhancement for H₂S and DATS detection.

Main Results:

• The Ag@Ag₂S core-shell nanostructures exhibited tunable properties based on H₂S concentration, influencing nanoparticle size, reporter molecule loading, and interparticle spacing.
• Achieved ultra-low detection limits: 151 ± 0.96 pM for H₂S and 6.6 ± 0.53 nM for DATS.
• Demonstrated high recovery rates (93.3%-111.0%) in actual water samples, validating the method's practical applicability.

Conclusions:

• The developed Ag@Ag₂S plasmonic arrays at the LLI offer a sensitive and effective platform for SERS-based detection of H₂S and DATS.
• This novel approach provides a promising new strategy for the trace detection of hazardous compounds in environmental monitoring.
• The method holds potential for practical applications in water quality assessment and related fields.