Detection of Multiple Pathogens in Serum Using Silica-Encapsulated Nanotags in a Surface-Enhanced Raman...

Area of Science:

• Biotechnology
• Analytical Chemistry
• Immunodiagnostics

Background:

• Accurate and rapid detection of multiple pathogenic antigens is crucial for timely disease diagnosis and monitoring.
• Existing diagnostic methods often require extensive sample preparation and lack the sensitivity or multiplexing capability for complex matrices like serum.

Purpose of the Study:

• To develop a highly sensitive and multiplexed immunoassay for the simultaneous detection of trace amounts of pathogenic antigens.
• To utilize surface-enhanced Raman scattering (SERS) for direct detection in complex biological samples, simplifying sample preparation.

Main Methods:

• Development of a robust immunoassay employing silica-encapsulated nanotags and magnetic nanoparticles conjugated with polyclonal antibodies.
• Utilized magnetic pull-down for immune complex aggregation, followed by SERS detection of distinct spectral fingerprints from captured antigens.
• Tested in 20% fetal bovine serum to assess performance in a complex biological matrix.

Main Results:

• Achieved simultaneous detection of antigens from West Nile virus, Rift Valley fever virus, and Yersinia pestis.
• Established a limit of detection of approximately 10 pg/mL, demonstrating significant improvement in sensitivity.
• Demonstrated enhanced multiplexing capability and reduced complexity compared to previous diagnostic approaches.

Conclusions:

• The developed SERS-based multiplex immunoassay platform offers high sensitivity and specificity for detecting multiple pathogens.
• This method eliminates the need for tedious sample preparation, making it suitable for on-site diagnostic testing.
• Provides a promising tool for real-time disease monitoring and rapid identification of infectious agents directly in crude serum samples.