Aptamer-modified metal-organic framework fiber network as a selective and recyclable affinity pretreatment column for aflatoxin B1 enrichment in feed.

A novel fireproof material@UIO-66-gold nanoparticles (AS@UIO-66-AuNPs) fiber network using low-cost fireproof material (AS) via an in-situ synthesis strategy has been developed. This functionalized network anchors specific aptamers (Apt), creating a highly efficient aptamer affinity column for the sensitive detection of aflatoxin B1 (AFB1) in food samples. Notably, this work focuses on the construction of an aptamer-based affinity pretreatment column rather than a signal-output sensing platform, aiming to improve target enrichment and matrix cleanup prior to instrumental analysis. Under optimized conditions, the method demonstrated excellent analytical performance, with a linearity range of 1–100 µg/kg and a detection limit of 0.157 µg/kg. Validation with spiked recovery experiments on corn, soybean meal, and rapeseed meal showed satisfactory recoveries and strong agreement with a commercial detection kit. The method also exhibited excellent reproducibility and reusability. Overall, the AS@UIO-66-AuNP/Apt system represents a cost-effective, stable, and selective strategy for the pretreatment and enrichment of AFB1, with potential applicability to other targets through aptamer replacement, thereby supporting the development of multifunctional aptamer affinity columns.