Ultrasensitive detection of SARS-CoV-2 S protein with aptamers biosensor based on surface-enhanced Raman scattering

Area of Science:

• Nanotechnology
• Biosensing
• Virology

Background:

• Rapid and accurate diagnostics are crucial for controlling SARS-CoV-2 transmission.
• Existing diagnostic methods may lack the speed or sensitivity required for effective pandemic management.

Purpose of the Study:

• To develop a rapid and ultrasensitive sensor for SARS-CoV-2 detection using surface-enhanced Raman scattering (SERS).
• To achieve high specificity by utilizing aptamers that target the SARS-CoV-2 spike protein.

Main Methods:

• A SERS-based sensor was designed using spherical cocktail aptamers-gold nanoparticles (SCAP) as the substrate and gold nanoparticles modified with Raman reporters and spike protein aptamers as nanoprobes.
• A sandwich structure was formed by targeting and capturing the SARS-CoV-2 S protein between the SCAP substrate and nanoprobes.
• Detection was achieved by monitoring changes in SERS peak intensity.

Main Results:

• The developed SERS assay demonstrated ultrasensitive detection of SARS-CoV-2 S protein with a limit of detection (LOD) below 0.7 fg mL⁻¹.
• The sensor detected pseudovirus at concentrations as low as 0.8 TU mL⁻¹ within approximately 12 minutes.
• Simulated oropharyngeal swab tests indicated the platform's potential for clinical application.

Conclusions:

• The proposed SERS sensor offers a rapid, ultrasensitive, and specific method for SARS-CoV-2 detection.
• This technology provides a potential new option for accurate diagnosis and improved control of SARS-CoV-2.
• The sensor's performance suggests its viability for clinical settings and public health surveillance.