SPR Biosensor Based on Bilayer MoS₂ for SARS-CoV-2 Sensing.

Area of Science:

• Nanomaterials Science
• Biosensor Technology
• Medical Diagnostics

Background:

• The COVID-19 pandemic necessitates rapid and sensitive diagnostic tools for SARS-CoV-2.
• Existing methods may lack the speed or sensitivity required for early detection.
• Surface Plasmon Resonance (SPR) biosensors offer label-free detection capabilities.

Purpose of the Study:

• To develop and optimize an SPR biosensor for enhanced SARS-CoV-2 detection.
• To investigate the impact of advanced materials like MoS2 and silicon nitride on SPR performance.
• To establish a sensitive and specific diagnostic tool for early viral detection.

Main Methods:

• Systematic optimization of SPR biosensor parameters: silver layer thickness, silicon nitride dielectric layer, MoS2 layers, and ssDNA recognition layer.
• Fabrication of the optimized SPR biosensor configuration.
• Performance evaluation using SARS-CoV-2 detection in PBS solution, measuring sensitivity, accuracy, and quality factor.

Main Results:

• The optimized SPR biosensor featured a 45 nm silver layer, 13 nm silicon nitride, 2 MoS2 layers, and a 5 nm ssDNA layer.
• Achieved high sensitivity (375.01°/RIU), detection accuracy (0.002), and quality factor (38.34) at 1.0 mM SARS-CoV-2 concentration.
• Demonstrated a linear response to refractive index changes, indicating quantitative analysis potential.

Conclusions:

• The integration of MoS2 and silicon nitride significantly enhances SPR biosensor performance for SARS-CoV-2 detection.
• The developed biosensor is a robust and precise tool for reliable SARS-CoV-2 detection, particularly for early diagnosis.
• The biosensor holds potential for clinical diagnostics and epidemiological monitoring of SARS-CoV-2.