Label-Free LSPR-Vertical Microcavity Biosensor for On-Site SARS-CoV-2 Detection

Area of Science:

• Nanotechnology
• Biosensing
• Plasmonics

Background:

• Effective control of the COVID-19 pandemic requires cost-effective, rapid, and sensitive high-throughput SARS-CoV-2 detection.
• Existing methods face challenges in speed, cost, and sensitivity for widespread application.

Purpose of the Study:

• To develop and assess a vertical microcavity and localized surface plasmon resonance (LSPR) hybrid biosensor for SARS-CoV-2 detection.
• To optimize the biosensor design using modeling and simulation for enhanced performance.

Main Methods:

• Fabrication of a hybrid biosensor integrating a vertical microcavity with nanoporous gold (NPG) structures.
• Immobilization of SARS-CoV-2 antibodies onto the NPG surface for virus capture.
• Utilizing reflectance spectrum valley shifts to detect changes in refractive index caused by virus binding.
• Optimization of microcavity and NPG parameters through modeling and simulation.

Main Results:

• NPG-deposited sensors demonstrated superior resonance quality and sensitivity compared to gold-deposited and pure microcavity sensors.
• Experimental validation confirmed the impact of NPG surface morphology on biosensor sensitivity.
• A 40% porosity NPG structure achieved the highest sensitivity, detecting SARS-CoV-2 pseudovirus at 319 copies/mL in artificial saliva.
• The automated system processed 100 samples within 30 minutes.

Conclusions:

• The proposed hybrid biosensor offers a sensitive and rapid method for SARS-CoV-2 detection.
• The system demonstrates significant potential for on-site, high-throughput coronavirus screening.
• Further development could facilitate real-time epidemic monitoring and control.