Core-shell structured gold nanoparticle-AIEgen nanohybrids for enhanced dual-mode lateral flow immunoassay of fumonisin B1.

Herein, we report the design and synthesis of bifunctional colorimetric and fluorescent nanohybrids (Au-AIENPs) through the co-assembly of oleylamine-modified gold nanoparticles (OA-AuNPs) and aggregation-induced emission luminogens (AIEgen). Due to the distinct compatibility of the components, the resulting Au-AIENPs form a core-shell nanostructure, with the AIEgen creating a fluorescent core and the OA-AuNPs uniformly dispersing on the shell. This spatial separation of AIEgen and OA-AuNPs optimizes the colorimetric signal while preserving a strong fluorescence output. Leveraging the intrinsic dual functionality of Au-AIENPs as dual-mode signal reporters, we demonstrate their potential for rapid, naked-eye visualization and fluorescent quantitative detection of fumonisin B1 (FB1) on the lateral flow immunoassay (LFIA) platform (Au-AIENPs-LFIA). Under optimal conditions, the developed Au-AIENPs-LFIA test strip achieved high sensitivity for FB1 qualitative detection, with a visual limit of detection (LOD) of 0.056 ng/mL, and exhibited ultrasensitivity for FB1 quantitative detection, with an LOD of 0.03 ng/mL. In conclusion, the proposed Au-AIENPs offer an ideal combination of visual compatibility and high sensitivity, providing significant practical implications for expanding LFIA applications, particularly in resource-limited settings.