Flexible Surface-Enhanced Raman Scattering Chip: A Universal Platform for Real-Time Interfacial Molecular Analysis...

Area of Science:

• Plasmonics
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman scattering (SERS) is a powerful technique for molecular detection.
• Existing SERS platforms often lack flexibility and real-time analysis capabilities for interfacial processes.
• Analyzing trace molecules on irregular surfaces or in solutions presents significant challenges.

Purpose of the Study:

• To develop and demonstrate a flexible SERS chip for highly sensitive, real-time interfacial molecule analysis.
• To achieve femtomolar detection limits and investigate chemical reactions at liquid interfaces.
• To establish SERS as a versatile tool for trace analysis and reaction mechanism elucidation.

Main Methods:

• Fabrication of a flexible SERS chip using a transparent membrane with embedded plasmonic dimers.
• Utilizing ultrahigh particle density and ultrasmall dimer gaps for enhanced sensitivity.
• Performing liquid-state measurements and in situ SERS analysis of chemical reactions.

Main Results:

• Achieved femtomolar (10^-14 mol·L^-1) detection limits for Rhodamine 6G, approaching single-molecule sensitivity.
• Demonstrated rapid identification of residuals on irregular solid substrates and dissolved analytes in aqueous solutions.
• Observed and analyzed the reduction of p-nitrothiophenol to p-aminothiophenol at liquid interfaces, driven by plasmon-induced hot electrons.

Conclusions:

• The flexible SERS chip is a robust platform for femtomolar detection and real-time interfacial analysis.
• The chip enables the study of chemical reactions, mechanism elucidation, and environmental effect evaluation.
• This approach extends SERS applications for identifying molecular traces and tracking reaction evolution.