Multiplexed SERS Detection of Serum Cardiac Markers Using Plasmonic Metasurfaces

Area of Science:

• Plasmonics
• Nanophotonics
• Biosensing

Background:

• Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity but struggles with quantitative analysis due to intensity fluctuations.
• The SERS uncertainty principle limits simultaneous enhancement and reproducibility.
• Existing SERS methods face challenges in reliable quantitative detection.

Purpose of the Study:

• To develop an integrated multiplexed SERS biosensing strategy for quantitative analysis.
• To overcome the limitations of SERS intensity fluctuations and the SERS uncertainty principle.
• To enable sensitive and reproducible detection of multiple analytes.

Main Methods:

• Fabrication of a subwavelength-structured plasmonic metasurface with alternately stacked metal-dielectric pyramidal meta-atoms.
• Harnessing nanomechanical perturbations to transduce signals as SERS frequency shifts.
• Utilizing 3D printing for fabricating the biosensing platform and demonstrating multiplexed detection.

Main Results:

• The plasmonic metasurface simultaneously enhances electric and magnetic fields, enabling spatially extended and weakly wavelength-dependent SERS.
• SERS frequency shifts were used as signals, unaffected by the SERS uncertainty principle, ensuring reproducibility.
• Successful proof-of-concept multiplexed detection of serum cardiac biomarkers for acute myocardial infarction was achieved.

Conclusions:

• The developed SERS biosensing strategy offers a potential solution for quantitative SERS analysis.
• The electric and magnetic field-active plasmonic metasurfaces enable new SERS substrate functionalities.
• Frequency shift-based SERS multiplexing opens avenues for innovative quantitative optical techniques in various scientific fields.