Photonic cavity and graphene modified plasmonic interface for enhanced sensing performance

Area of Science:

• Optoelectronics
• Nanotechnology
• Biomedical Engineering

Background:

• Surface Plasmon Resonance (SPR) biosensors are crucial for biomolecular detection.
• Enhancing SPR sensitivity and bioaffinity remains a key research challenge.
• Existing methods often face limitations in resolution and fabrication.

Purpose of the Study:

• To propose and experimentally validate a novel SPR biosensor.
• To enhance sensitivity and bioaffinity through integrated modulation coupling and monolayer graphene.
• To achieve superior performance for biomedical applications.

Main Methods:

• Fabrication of a one-dimensional photonic crystal (PC) cavity with alternating dielectric layers (Ta2O5 and Al2O3) on a gold film.
• Integration of monolayer graphene to further boost sensitivity.
• Utilizing Finite-Element Method (FEM) for structural optimization and Fast Fourier Transform (FFT) for noise filtering.

Main Results:

• Achieved a high figure of merit (FOM) and sensitivity, reaching 8900 nm/RIU theoretically and 8052 nm/RIU experimentally.
• Experimental sensitivity increased to 8128.3 nm/RIU with graphene integration.
• Demonstrated a 3.7-fold higher resonance shift for human immunoglobulin G detection compared to conventional methods.

Conclusions:

• The proposed SPR biosensor design offers enhanced sensitivity, resolution, and bioaffinity.
• The integration of PC cavities and graphene presents a promising strategy for advanced biosensing.
• This technology has significant potential for diverse biomedical applications requiring precise detection.