Integrating Single Domain Antibodies into Field-Deployable Rapid Assays

Area of Science:

• Biotechnology
• Immunology
• Assay Development

Background:

• Single domain antibodies (sdAbs) offer advantages over conventional antibodies, including small size, stability, and cost-effective production.
• However, sdAbs' high solubility can impede their efficient attachment to surfaces, complicating assay development.
• Optimizing sdAb integration is crucial for applications like point-of-care testing and field diagnostics.

Purpose of the Study:

• To engineer single domain antibody (sdAb)-based constructs for improved performance in rapid vertical flow assays.
• To develop generalizable protocols for attaching sdAbs to gold nanoparticles and support membranes.
• To enhance the sensitivity and utility of sdAb-based assays for detecting biothreat agents and viral proteins.

Main Methods:

• Protein engineering of sdAb constructs for enhanced surface adhesion.
• Development of protocols for conjugating sdAbs to gold nanoparticles.
• Establishment of methods for immobilizing sdAbs onto support membranes for vertical flow assays.

Main Results:

• Achieved a limit of detection of 0.11 µg/mL for staphylococcal enterotoxin B and ricin.
• Successfully detected the nucleocapsid protein of SARS-CoV-2.
• Demonstrated optimized protocols for sdAb attachment, overcoming previous limitations.

Conclusions:

• Engineered sdAbs can be effectively integrated into rapid vertical flow assays.
• The developed protocols facilitate the use of sdAbs in sensitive diagnostic applications.
• This approach enables robust detection of biothreat agents and viral pathogens in field settings.