A Au nanoparticle-incorporated sponge as a versatile transmission surface-enhanced Raman scattering substrate

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Developing sensitive and quantitative analytical substrates is crucial for detecting analytes in complex matrices.
• Traditional surface-enhanced Raman scattering (SERS) substrates often face limitations in sample handling and quantitative accuracy.
• Transmission mode measurements offer potential for improved quantitative representation of sample concentration.

Purpose of the Study:

• To develop a novel sponge-based transmission surface-enhanced Raman scattering (TSERS) substrate.
• To combine the advantages of bulk sampling with the properties of sponges for enhanced SERS analysis.
• To evaluate the substrate's performance for quantitative detection and sample enrichment.

Main Methods:

• Selection and characterization of a suitable sponge material (melamine sponge).
• Preparation of gold nanoparticle-incorporated sponges (AuNP sponges) via simple soaking.
• Evaluation of the AuNP sponges as TSERS substrates using 4-nitrobenzenethiol (4-NBT) at various concentrations.
• Assessment of sample enrichment capabilities through repeated suctioning and solvent depletion.
• Analysis of paraquat in diverse matrices (de-ionized water, tap water, river water, orange juice).

Main Results:

• Melamine sponges were chosen for their fast sample uptake and low background Raman signal.
• AuNP sponges demonstrated clear intensity variations with 4-NBT concentration, showing good quantitative potential (RSD of 10.0%).
• Sample enrichment using the AuNP sponges effectively doubled the signal intensity.
• Paraquat was successfully detected in various complex matrices, with signal intensity correlating inversely with matrix complexity.

Conclusions:

• The developed TSERS sponge substrate is easy to prepare and offers excellent sample handling properties.
• The substrate provides a versatile and quantitative platform for SERS analysis of diverse analytes in complex samples.
• This sponge-based TSERS approach holds significant promise for practical analytical applications.