Click chemistry driven aggregate reaction dramatically enhances the sensitivity of dynamic light scattering...

Area of Science:

• Biosensing
• Chemical Engineering
• Immunotechnology

Background:

• Traditional dynamic light scattering (DLS) immunosensors couple immune recognition and signal transduction, limiting sensitivity due to suboptimal antigen-antibody interactions.
• Inefficient target valency and aggregation efficiency in conventional DLS immunosensors restrict their detection capabilities for trace analytes.

Purpose of the Study:

• To develop a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC)-amplified DLS immunosensor (CAD-immunosensor) that decouples immune recognition from click chemistry-driven aggregation.
• To enhance the sensitivity, reduce detection time, and simplify sample preparation for DLS immunosensors.

Main Methods:

• Utilized Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) for covalent aggregation of immunocomplexes via a polyvalent protein crosslinker.
• Investigated protein crosslinker valency and spatial configuration to optimize immunocomplex aggregation kinetics and efficiency.
• Evaluated the CAD-immunosensor for detecting staphylococcal enterotoxin A and malachite green.

Main Results:

• Achieved a limit of detection of 0.70 pg/mL for staphylococcal enterotoxin A, representing significant sensitivity improvements over conventional DLS immunosensors and ELISA.
• Demonstrated a 3675-fold increase in sensitivity for malachite green detection compared to ELISA.
• Reduced test time from 90 minutes (ELISA) to 25 minutes (CAD-immunosensor) and simplified sample preparation.

Conclusions:

• The CAD-immunosensor successfully decouples immune recognition from click chemistry-driven aggregation, leading to significantly enhanced probe aggregation efficiency.
• The developed immunosensor offers ultrasensitive detection of trace analytes with improved sensitivity, reduced assay time, and robust performance.
• The CAD-immunosensor shows strong potential for practical applications in detecting various analytes, including food contaminants and toxins.