Dual-mode screening system for rapid and accurate aflatoxin B1 detection in edible oils

This study established a dual-mode system integrating a portable flow cytometer with UHPLC-QqQ MS/MS for rapid AFB1 detection in edible oils. A competitive immunofluorescence sensor used streptavidin-magnetic microspheres with biotin-AFB1-BSA, AFB1 antibody, and APC-labeled secondary antibody. The method showed a linear range of 0.025-25 ng/g (R² = 0.9966), with IC10 of 0.26 ng/g and IC50 of 0.76 ng/g. Recoveries were 90.51-102.73% with precisions ≤9.54%. UHPLC-QqQ MS/MS achieved LODs of 0.20-0.40 ng/g and LOQs of 0.50-1.25 ng/g for AFB1, AFB2, AFG1, and AFG2, with recoveries of 88.99-107.12% and precisions of 1.09-10.58%. Validation with 29 commercial oils and 10 contaminated peanut batches found no AFB1 in market samples and 1.07-9.36 ng/g in contaminated ones, consistent with UHPLC-QqQ MS/MS. The system enables on-site high-throughput screening with a flow cytometric reading speed of approximately 1 min per sample and a batch throughput of ∼32 samples/h (96-well plate format), while maintaining laboratory-grade accuracy. By enabling efficient triage of large sample volumes at the point of sampling, this strategy provides a practical and cost-effective framework for strengthening aflatoxin surveillance in the edible oil supply chain.