Synergistic immune-network-oriented probe based on pCuGA-AFcI for enhanced on-site detection of pentachlorophenol

Area of Science:

• Nanotechnology and Materials Science
• Bioconjugation Chemistry
• Analytical Chemistry and Immunoassays

Background:

• Antibody (Ab) immobilization on nanoparticles is crucial for immunochromatographic assay (ICA) performance.
• Current methods face challenges with Ab shedding and suboptimal orientation, impacting assay sensitivity and stability.
• There is a need for improved strategies to enhance Ab binding stability and assay efficiency.

Purpose of the Study:

• To develop a novel immune-bridging mechanism for stabilizing antibody binding in ICAs.
• To create a bio-derived tracer modified with anti-Fc immunoglobulins (AFcI) for enhanced antibody orientation and stability.
• To improve the sensitivity and detection limits of ICAs through optimized tracer design.

Main Methods:

• A bio-derived tracer, pupal-like CuGA (pCuGA), was synthesized from Cu2+ and gallic acid (GA).
• The pCuGA tracer was modified with AFcI to create an immune-bridging interaction with antibodies (Abs).
• The pCuGA-AFcI-Ab tracer was incorporated into an ICA for performance evaluation against conventional probes.

Main Results:

• The pCuGA-AFcI-Ab tracer demonstrated enhanced stability and synergistic Ab orientation, forming an immune-network.
• The new ICA probe halved Ab consumption and achieved significantly lower detection limits (IC10 of 0.019 ng/mL).
• The method showed high sensitivity (3.2-fold enhancement) and a low cut-off value (3.00 ng/mL, 4.0-fold enhancement), validated in diverse real-world samples.

Conclusions:

• The immune-bridging strategy using AFcI-modified tracers offers a robust method for stabilizing antibody binding in ICAs.
• This approach significantly enhances assay sensitivity, reduces Ab usage, and lowers detection limits.
• The study presents a green and versatile platform for functional modification of ICA tracers, advancing diagnostic capabilities.