The preparation of immunomagnetic beads based on oriented Ab and its application for AFB1 enrichment

The escalating issue of Aflatoxin B1 (AFB1) contamination has posed an alarming concern worldwide. Enrichment efficiency is crucial to accurately detecting trace amounts of AFB1. Immunomagnetic beads (IMBs) enrichment is beneficial for reducing operation time and labor intensity. In this work, oriented MBs@PG@mAbs was prepared as novel IMBs while MBs@SA@mAbs and MBs@mAbs were prepared as traditional IMBs. At equivalent antibody coupling amounts, the normalized Fab orientation of MBs@PG@mAbs, MBs@SA@mAbs, and MBs@mAbs were 100, 70.7, and 68.0%, respectively. The MBs@PG@mAbs exhibit good AFB1 enrichment, with a maximum capture efficiency of 96.2%, and the capture efficiencies of MBs@SA@mAbs, and MBs@mAbs were 95.8 and 94.9%, respectively. The reliability and practicability of the proposed MBs@PG@mAbs for AFB1 enrichment were further evaluated using AFB1-spiked maize samples. The recoveries of MBs@PG@mAbs were 97.6, 95.0 and 94.2% when 2, 5 and 10 ng/g AFB1 were spiked in samples. The quantitative analysis results of the AFB1 in actual maize samples by MBs@PG@mAbs-ELISA and LC-MS/MS were consistent. Thus, the PG-mediated coupling method led to the most efficient enrichment performance and had the potential for further applications.