WS₂/Si₃N₄-Based Biosensor for Low-Concentration Coronavirus Detection.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Infectious Disease Diagnostics

Background:

• Accurate and rapid detection of SARS-CoV-2 is critical for controlling viral spread.
• Surface Plasmon Resonance (SPR) biosensors offer label-free detection capabilities.
• Optimization of SPR sensor configurations is necessary to enhance sensitivity and reduce detection limits.

Purpose of the Study:

• To optimize two SPR biosensor configurations, Sys3 and Sys5, for the detection of SARS-CoV-2.
• To evaluate the performance metrics including sensitivity, signal-to-noise ratio, figure of merit, and limit of detection.
• To assess the diagnostic potential of the optimized biosensors for clinical samples.

Main Methods:

• Fabrication and characterization of two SPR biosensor designs (Sys3 and Sys5) with varying layer compositions (silver, silicon nitride, ssDNA, tungsten disulfide).
• Performance evaluation using key metrics such as Figure of Merit (FoM), Signal-to-Noise Ratio (SNR), Detection Accuracy (DA), sensitivity, and Limit of Detection (LoD).
• Analysis of sensor performance in relation to the refractive index ranges of clinical SARS-CoV-2 samples.

Main Results:

• Sys3 achieved a FoM of 571.24 RIU^-1, SNR of 0.12, and DA of 48.93 × 10^-2, with high precision (<1% attenuation).
• Sys5 demonstrated superior sensitivity (305.33 °/RIU) and a lower LoD (1.65 × 10^-5), crucial for early viral detection.
• Both optimized configurations align with the refractive index characteristics of clinical SARS-CoV-2 samples.

Conclusions:

• Optimized SPR biosensors, particularly Sys5, exhibit enhanced sensitivity and lower detection limits for SARS-CoV-2.
• The developed biosensors show significant potential for accurate and sensitive viral diagnostics.
• Future research will focus on experimental validation and integration into point-of-care diagnostic platforms.