Topology-engineered dopamine-mediated flower-like gold nanoparticle adjuvants: Boosting immune responses and enabling sensitive immunoassays for albendazole residue detection.

BACKGROUND

Albendazole (ABZ) exhibited teratogenic and embryotoxic effects in diverse animal species, implying comparable risks to humans; residues derived from improper veterinary use can enter the food chain via transfer, ultimately endangering human health. To obtain efficient anti-albendazole (ABZ) monoclonal antibodies and establish a sensitive detection sensor, we prepared a novel nano-adjuvant, topologically engineered dopamine-mediated flower-like gold nanoparticles (PANFs), for stimulating immune responses. Computer-aided techniques simulated antigen-antibody recognition sites. Immunoprobes were constructed using gold nanoparticles (AuNPs) as labeling materials, establishing an immunochromatographic detection method for ABZ in meat products.

RESULTS

Experimental data demonstrated that PANFs with a high branching density topology significantly enhanced the immunostimulatory effect. Their mechanism of action involves regulating the directed differentiation of CD4+ T cells to Th2 subpopulations and inducing the upregulation of Th2-type cytokines such as IL-4 and IL-6. These cytokines activate Th2-type immune response pathways. Further studies showed that the introduction of highly branched PANF3 significantly increased the potency of ABZ-specific antibodies in mouse serum. A monoclonal antibody strain (4H1) against ABZ with an IC50 of 0.727 ng mL-1 was finally obtained. Molecular recognition studies revealed the interaction between 4H1 antibody and ABZ, which arises from halogen bonds and π-alkyl interactions, identifying key amino acid sites. Finally, a immunoassay was established and achieved sensitive detection (LOD = 2.86 μg kg-1) of ABZ in chicken samples. The recoveries of cascade AuNPs-LFIA were 85.20% to 114.40%, with coefficients of variation consistently below 8.66%.

SIGNIFICANCE: These findings emphasized the critical role of the morphology of nanoparticles with high branching densities in regulating the intracellular fate of nanoparticles, which may provide insights for engineering nanocarriers. The developed sensor can realize rapid, sensitive and accurate on-site detection of ABZ in meat, which not only improved the efficiency of veterinary drug residue screening, but also provided a efficient technical means for the whole-process quality control of meat products.