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Published on: June 23, 2022
Plasmonic Gold Prism Array for Digital Surface-Enhanced Raman Spectroscopy Sensing
Peng Zheng1, Lintong Wu1, Ishan Barman2
1Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, United States.
Summary
A new gold prism array enables digital surface-enhanced Raman spectroscopy (SERS) by leveraging signal fluctuations for femtomolar detection. This plasmonic substrate offers enhanced sensitivity for various analytical applications.
Area of Science:
- Plasmonics
- Spectroscopy
- Nanomaterials
Background:
- Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique limited by signal fluctuations due to dynamic molecule-metal interactions.
- Quantitative SERS analysis at ultralow concentrations is compromised by these fluctuations.
- Digital SERS offers a novel approach by utilizing signal stochasticity for enhanced detection limits.
Purpose of the Study:
- To develop superior two-dimensional plasmonic substrates for routine digital SERS analysis.
- To introduce and characterize a plasmonic gold prism array for digital SERS sensing.
- To demonstrate femtomolar level detection using the gold prism array.
Main Methods:
- Fabrication of a plasmonic gold prism array.
- Characterization of plasmonic properties, including scattering and surface features.
- Utilizing digital SERS approach with a predefined signal threshold.
- SERS measurements using 4-aminothiophenol as a model analyte.
Main Results:
- The gold prism array exhibits strong scattering and nanoparticle-like surface features, providing plasmonic enhancement beyond vertex and edge modes.
- SERS hotspots were predominantly observed at the center of the gold prisms, contrary to expectations.
- Digital SERS sensing was successfully demonstrated at the femtomolar level.
Conclusions:
- The plasmonic gold prism array serves as a superior substrate for digital SERS.
- This platform enables highly sensitive molecular detection, pushing the limits of current SERS capabilities.
- The gold prism array holds significant potential for applications in diagnostics, environmental monitoring, and food safety.
