Biosynthetic Mycotoxin Conjugate Mimetics-Mediated Green Strategy for Multiplex Mycotoxin Immunochromatographic Assay

Various mycotoxins widely co-exist in agro-products, and their combined effects cause toxicity and potential carcinogenicity to humans and animals. In this work, we developed an economical and sensitive quantum dots (QDs)/QD microbead (QDs/QB)-based multiplex immunochromatographic assay (mICA) for the rapid detection of fumonisin B₁ (FB₁), zearalenone (ZEN), and ochratoxin A (OTA) without the building-up process of mycotoxin conjugates. QDs and QBs were selected as fluorescent reporters and conjugated with antimycotoxin monoclonal antibodies for improving sensitivity. Furthermore, phage-displayed FB₁, ZEN, and OTA mimotope peptide-based soluble and monovalent fusions to maltose-binding protein (MBP) were applied onto the test line of the mICA as the mimetic coating antigen. Under the optimized conditions, the visual detection limits (vLODs) of peptide-MBP-based mICA could be obtained as 0.25 ng/mL for FB₁, 3.0 ng/mL for ZEN, and 0.5 ng/mL for OTA within 10 min. The results for spiked real sample detection indicate good accuracy, reproducibility, and practicability. In addition, the proposed mICA was comparable with ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) in terms of reliability in detecting FB₁, ZEN, and OTA using natural samples. From the point of promoting commercial production, these time-saving and low-cost peptide-MBP antigens applied in ICA might provide promising potential for promoting productivity and decreasing the cost of production.