A THz graphene metasurface for polarization selective virus sensing

Area of Science:

• Terahertz (THz) spectroscopy
• Plasmonics
• Nanophotonics

Background:

• Graphene plasmonic metasurfaces offer high sensitivity for biosensing.
• Chirality in metasurfaces can be exploited for polarization-based detection.
• Characterizing virus refractive index (RI) is crucial for diagnostics.

Purpose of the Study:

• To develop a novel method for virus RI characterization using chiral graphene metasurfaces.
• To detect and discriminate between different Avian Influenza (AI) virus strains.
• To simplify virus detection instrumentation compared to traditional methods.

Main Methods:

• Designing a dispersive graphene metasurface to generate chiral surface currents.
• Coupling linearly polarized incident THz fields to circularly polarized reflected fields.
• Analyzing changes in reflected field polarization (ellipticity) to determine RI.
• Utilizing a pre-calculated calibration model based on full-wave electromagnetic simulations.

Main Results:

• Demonstrated rapid changes in polarization ellipticity correlated with virus RI.
• Successfully discriminated between three types of Avian Influenza (AI) viruses (H1N1, H5N2, H9N2).
• Showcased the method's sensitivity to complex refractive index variations.

Conclusions:

• Chiral graphene metasurfaces provide a sensitive platform for virus RI characterization.
• The polarization-selective sensing method offers a simpler alternative to broadband spectroscopic techniques.
• This approach facilitates rapid and specific identification of viral pathogens.