Highly selective monoclonal antibody-based lateral flow immunoassay for visual and sensitive determination of conazole fungicides propiconazole in vegetables

ABSTRACT

The conazole fungicide propiconazole is frequently found in vegetables although usage is not allowed. To overcome the high-cost and time-consuming labour requirements of instrumental methods, we developed a simple and visual lateral flow immunoassay for the sensitive determination of propiconazole. A hapten was carefully designed to raise a monoclonal antibody against propiconazole. Bal b/c mice were immunised with the hapten-carrier protein conjugate and a specific monoclonal antibody (mAb) was produced. Based on this mAb, a sensitive immunochromatographic strip assay (ICA) was established for rapid screening of propiconazole in vegetable samples. After optimisation of analytical parameters, the ICA strip showed a detection limit of 0.13 ng g⁻¹ and a linear range from 0.5 to 80 ng g⁻¹ using a strip reader. The assay also can be read by the naked eye with a visual limit of detection of 80 ng g⁻¹. The recoveries for spiked vegetable samples by ICA ranged from 85.2% to 114.9%, with a coefficient of variation less than 11.7%. The assay time is within 45 min for a single sample including the sample pre-treatment. For spiked and blind samples, the detection capability of ICA was equivalent to liquid chromatography-mass spectrometry.

GRAPHICAL ABSTRACT

KEYWORDS:

• Propiconazole
• monoclonal antibody
• immunochromatographic test strip
• rapid detection

Author contribution

Ze-Ke Xu: designing the study, experiment and writing the initial draft of the manuscript. Jing-Nan Meng: designing the study, experiment and writing the initial draft of the manuscript. Yi-Lei: analysis and interpretation of data. Xing-Xing Yang: analysis and interpretation of data. Yi-Yong Yan: analysis and interpretation of data. Hai-Hong Liu: analysis and interpretation of data and assisting in the preparation of the manuscript. Hong-Tao Lei: analysis and interpretation of data and assisting in the preparation of the manuscript. Ting-Cai Wang: analysis and interpretation of data and assisting in the preparation of the manuscript. Xing Shen: designing the study, and reviewing and editing of the manuscript, Writing–reviewing and editing. Zhen-Lin Xu designing the study, and reviewing and editing of the manuscript, Writing–reviewing and editing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

The animal involved in the experiments were performed according to the Regulation Guideline for Experimental Animals issued by the Ministry of Science and Technology of China.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This work was supported by the National Key Research and Development of China [2017YFC1601700; 2018YFC1602903; 2018YFC1602904], the Generic Technique Innovation Team Construction of Modern Agriculture of Guangdong Province (2019KJ130), the Key Project of Guangdong Provincial High School (2019KJDXM002, 2019SCAUGH03).