Development of a Homologous Fluorescence Polarization Immunoassay for Diisobutyl Phthalate in Romaine Lettuce

作者：Chen, Yingshan; Cui, Xiping; Wu, Panpan; Jiang, Zhengyun; Jiao, Luoying; Hu, Qingqing; Eremin, Sergei A.; Zhao, Suqing^*

来源：Food Analytical Methods, 2017, 10(2): 449-458.

DOI：10.1007/s12161-016-0596-1

• Fluorescence polarization immunoassay
• Phthalate acid esters
• Diisobutyl phthalate
• Romaine lettuce

In this work, three fluorescein-labeled DiBP derivatives (tracers) with different chemical structures and spacer bridges were synthesized and purified by thin-layer chromatography (TLC). Compared with the heterologous tracer, the homologous tracer exhibited more affinity to the antibody. What is more, the tracer concentration and the antibody dilution were further evaluated to improve the sensitivity of fluorescence polarization immunoassay (FPIA). On the basis of sensitive antibody and tracer, a rapid and specific FPIA has been established for the detection of DiBP contamination in the romaine lettuce, which has rarely been reported before. Under the optimal conditions, the developed FPIA showed a good detection range from 8.82 to 2152.84 ng/mL, with a detection limit of 1.77 ng/mL. In addition, the cross-reactivity to several compounds structurally related to DiBP was less than 7.37 %. Therefore, DiBP contamination in spiked romaine lettuce samples was detected by FPIA, with the recovery from 88.28 to 119.11 %. Moreover, when compared with high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA), the results analyzed by the developed FPIA shows a strong reliability and a high correlation value of 0.978 and 0.980, respectively. Thus, this data, combined with rapidity and simplicity of the assay, demonstrates that the established FPIA is a suitable method for high throughput screening of DiBP contamination in the romaine lettuce.

• 出版日期2017-2
• 单位广东工业大学