A disposable paper-based hydrophobic substrate for highly sensitive surface-enhanced Raman scattering detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Surface-enhanced Raman scattering (SERS) requires sensitive and reproducible substrates, which are often costly.
• Current SERS substrates face challenges in analyte concentration and nanoparticle aggregation, limiting detection sensitivity.

Purpose of the Study:

• To develop a cost-effective, highly sensitive, and reproducible hydrophobic SERS substrate.
• To enhance analyte and nanoparticle concentration for improved SERS detection.
• To demonstrate the substrate's utility in detecting biomolecules and cells.

Main Methods:

• Fabrication of a hydrophobic SERS substrate by spin-coating lubricating liquid onto commercial paper.
• Utilizing the condensation effect of the paper-based substrate to induce gold nanoparticle aggregation and analyte concentration.
• Evaluating SERS signal intensity, limit of detection (LOD), and reproducibility.

Main Results:

• The hydrophobic substrate achieved a 5-fold increase in SERS signal intensity compared to common paper.
• A low LOD of 4.3 × 10^-10 M for rhodamine 6G (R6G) was obtained.
• High reproducibility was demonstrated with a relative standard deviation (RSD) of approximately 11%.

Conclusions:

• The developed hydrophobic paper-based SERS substrate offers a cost-effective and highly sensitive platform for analyte detection.
• The substrate enables sensitive detection of biomolecules like cytochrome C and differentiation of cancer and non-cancer cells.
• This disposable substrate effectively addresses solution diffusion issues and provides a versatile tool for biomolecular screening.