Portable Multiplex Immunochromatographic Assay for Quantitation of Two Typical Algae Toxins Based on Dual-Color Fluorescence Microspheres

• Published in: Journal of agricultural and food chemistry 2019-05, Vol.67 (21), p.6041-6047
• Main Authors: Zhang, Huiyan, Luo, Jiaxun, Beloglazova, Natalia, Yang, Shupeng, De Saeger, Sarah, Mari, Ghulam Mujtaba, Zhang, Suxia, Shen, Jianzhong, Wang, Zhanhui, Yu, Xuezhi
• Format: Article
• Language: English
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.9b00011

A multiplex immunochromatographic assay (ICA) based on dual-color fluorescent microspheres (FMs) as a sensitive label was developed for the first time. Two typical algae toxins, microcystin-LR (MC-LR) and okadaic acid (OA), were chosen as proof-of concept targets to evaluate the feasibility of this ICA format. Commercial red- and green-colored FMs were selected to couple with monoclonal antibodies as fluorescent probes. The use of dual-wavelength FMs as labels guaranteed a lower consumption of material strips, lower sample volume, and shorter reaction time without increasing the length of ICA strips. Under optimal conditions, the multiplex FM-ICA could be completed in 20 min and reached limits of detection for the simultaneous determination of MC-LR and OA in fish samples, which were 0.074 and 2.42 μg/kg, respectively. The developed technique was validated using artificially spiked and naturally contaminated fish samples. Ultra-high-performance liquid chromatography-tandem mass spectrometry was used as confirmatory technique. In summary, this portable ICAs detection mode based on dual-wavelength FMs provided a reliable and sensitive on-site detection of multiple contaminants in food samples, which opens a new field for application of FMs in food safety.