A dual-functional magnetic-fluorescent nanobead-based multi-color lateral flow immunoassay for simultaneous detection of aflatoxin B1 and zearalenone.

Herein, we developed a lateral flow immunoassay (LFIA) based on dual-functional magnetic-fluorescent nanobeads for the simultaneous detection of aflatoxin B1 (AFB1) and zearalenone (ZEN). Magnetic quantum dot nanobeads (MQBs) were synthesized by encapsulating CdSe/ZnS quantum dots and iron oxide nanoparticles into polystyrene nanobeads. These MQBs exhibit excellent superparamagnetic and fluorescent properties, enabling the dual functions of target purification and signal output in the LFIA, effectively reducing matrix interference. Further, a multi-color LFIA was developed with red and green MQBs probes, which can independently monitor the effectiveness of individual antibodies through the C-line color. The method demonstrated high sensitivity, with detection limits of 6.5 pg/mL (AFB1) and 86.4 pg/mL (ZEN). In spiked feed and maize, the recoveries were 80.6%∼103.4%, with relative standard deviations under 10.1%. The MQBs-LFIA can rapidly detect trace AFB1 and ZEN in complex matrices, serving as a promising method for feed and food safety supervision.