Optical Detection of SARS-CoV-2 Utilizing Antigen-Antibody Binding Interactions

Area of Science:

• Biophotonics and Biosensing
• Molecular Diagnostics
• Virology

Background:

• The COVID-19 pandemic, caused by SARS-CoV-2, necessitates rapid and accessible diagnostic tools.
• Current diagnostic methods can be time-consuming or require specialized laboratory equipment.
• Optical detection methods offer potential for portable and cost-effective diagnostics.

Purpose of the Study:

• To investigate the optical detection of SARS-CoV-2 using antigen-antibody binding.
• To develop a proof-of-concept for detecting SARS-CoV-2 proteins with smartphone-based spectrophotometry.
• To analyze the optical responses indicative of specific molecular interactions.

Main Methods:

• Utilizing antigen-antibody binding interactions for detection.
• Employing a smartphone light source and a portable spectrophotometer.
• Detecting soluble spike protein subunits and whole SARS-CoV-2 proteins.
• Analyzing binding interactions of RBD and NCP proteins with their antibodies.
• Applying principle component analysis for enhanced detection in mixtures.

Main Results:

• Demonstrated optical detection of SARS-CoV-2 spike protein subunits.
• Confirmed binding potential of SARS-CoV-2 proteins with corresponding antigens.
• Observed a distinct "hump or spike" in light intensity during specific molecular interactions.
• Showcased the ability to analyze optical responses for precise target identification.

Conclusions:

• Developed a feasible optical detection strategy for SARS-CoV-2.
• Validated the use of smartphone-based spectrophotometry for viral protein detection.
• Highlighted the potential of optical responses and PCA for sensitive and specific diagnostics.