Multiplex bio-barcode based fluorometric immunoassay for simultaneous determination of zearalenone, fumonisin B1, ochratoxin A, and aflatoxin B1 in cereals

• Published in: Food control 2023-08, Vol.150, p.109759, Article 109759
• Main Authors: Huang, Na, Sheng, Wei, Bai, Dongmei, Sun, Meiyi, Ren, Lishuai, Wang, Shuo, Zhang, Wanli, Jin, Zixin
• Format: Article
• Language: English
• Subjects: aflatoxin B1; barcoding; Bio-barcode; detection limit; dithiothreitol; fluorescence; Fluorescence-quenched immunoprobes; Fluorometric immunoassay; fluorometry; food safety; freeze-thaw cycles; fumonisin B1; immunoassays; Mycotoxins; nanogold; ochratoxin A; quantitative analysis; Simultaneous detection; single-stranded DNA; zearalenone
• ISSN: 0956-7135; 1873-7129
• DOI: 10.1016/j.foodcont.2023.109759

In this work, a fluorometric immunoassay based on multiple fluorophore-labeled barcodes was developed for simultaneous quantitative detection of zearalenone (ZEN), fumonisin B1 (FB1), ochratoxin A (OTA), and aflatoxin B1 (AFB1) in cereal samples. Gold nanoparticles (AuNPs) were firstly modified with four mycotoxins antibodies, and then the resultant AuNPs-antibodies conjugates were functionalized with different fluorophore-labeled single-stranded DNA (ssDNA) by a freeze-thaw strategy to prepare the fluorescence-quenched immunoprobes. In one test process, the quenched fluorescence was effectively recovered via dithiothreitol (DTT) and four fluorescence signals from immunoprobes were tested simultaneously for the quantitative analysis of four mycotoxins. This work has shown good test sensitivity of assay with the limit of detection (LOD) as 0.004 μg/L for ZEN, 0.483 μg/L for FB1, 0.006 μg/L for OTA, and 0.013 μg/L for AFB1. The LODs for detection of ZEN, FB1, OTA, and AFB1 in cereal samples are 0.02 μg/kg, 2.42 μg/kg, 0.03 μg/kg, and 0.065 μg/kg, respectively. The proposed assay can serve as a promising sensitive and high-throughput detection platform for monitoring multiplex targets in a single run. [Display omitted] •Time-saving and efficient freeze-thaw strategy is applied to prepare immunoprobe.•Simultaneous quantitative test of four mycotoxins is achieved in one test process.•UPLC-MS/MS confirms that this method has good reliability and practicability.