Dual-Readout Sandwich Immunoassay for Device-Free and Highly Sensitive Anthrax Biomarker Detection

Area of Science:

• Biotechnology
• Nanotechnology
• Immunotechnology

Background:

• Immunoassays are crucial for disease biomarker detection.
• Gold nanoparticles (AuNPs) offer versatile applications in biosensing.
• Sensitive and device-free detection methods are highly desirable.

Purpose of the Study:

• To develop a dual-readout, AuNP-based sandwich immunoassay.
• To enable both colorimetric and scanometric detection of disease biomarkers.
• To discover a novel antibody pair for anthrax protective antigen (PA83) detection.

Main Methods:

• Utilized AuNP-antibody conjugates for signal transduction and amplification.
• Employed platinum or gold deposition for colorimetric or scanometric signal generation.
• Applied a platinum-based colorimetric readout for monoclonal antibody (mAb) discovery.

Main Results:

• Identified a mAb sandwich pair for PA83 detection with 1 nM sensitivity in PBS and 5 nM in human serum.
• Achieved subpicomolar PA83 detection using gold deposition for scanometric readout.
• Scanometric detection demonstrated over 3 orders of magnitude higher sensitivity than colorimetric detection.

Conclusions:

• The developed dual-readout immunoassay provides a sensitive and versatile platform for biomarker detection.
• The scanometric readout offers significantly enhanced sensitivity for disease biomarkers.
• This assay has potential applications in diagnostics and disease surveillance.