A sensitive immunochromatographic assay using colloidal gold–antibody probe for rapid detection of fumonisin B₁ in corn

ABSTRACT

A sensitive immunochromatographic assay (ICA) using a colloidal gold–antibody probe for the rapid detection of fumonisin B₁ (FB₁) in corn samples was developed. The colour density of the test line correlated with the concentration of FB₁ in the range 2–40 ng ml^–1 by the assay, and the detection limit for FB₁ was 2 ng ml^–1. The linear range for FB₁ was 50–1000 µg kg^–1, and the visual limit detection of the test was 1000 µg kg^–1 in corn samples. The ICA to detect FB₁ is sensitive, specific and rapid. Specific anti-FB₁ monoclonal antibody (mAb) and FB₁-ovalbumin (FB₁-OVA) conjugate antigen were prepared. FB₁ mAb, labelled with colloidal gold, was used as the probe on the immunochromatographic strip. FB₁-OVA and goat-anti-mouse IgG were coated onto a nitrocellulose (NC) membrane as test lines and control lines, respectively. FB₁ in samples will competitively combines the FB₁ mAb with the FB₁-OVA in an NC membrane and the results are directly observed by the colour of the detection and quality control lines. The concentrations of FB₁ mAb labelled with colloidal gold, detecting antigen and goat anti-mouse IgG, were optimised. The results indicate that the test strip is specific for FB₁, with no cross-reactivity to other toxins. The strip assay for FB₁ was simple, only needing one step without complicated assay performance and expensive equipment, and the total time for visual evaluation was less than 10 min. A survey of 24 corn samples from Hefei, China, was performed with the test strip and HPLC, and the detection results showed that the developed ICA and the HPLC were in excellent agreement. Hence, the developed ICA can be used as a method for rapid detection of FB₁ in corn samples.

KEYWORDS:

• Fumonisin B₁
• monoclonal antibody
• immunochromatographic assay
• detection
• corn

Acknowledgements

Xi-Chun Wang, Hai-Xin Fan and Meng-Xue Fan contributed equally to the writing of this paper. The final manuscript was read and approved by all the authors. The authors thank the anonymous reviewers for their kind advice.

Disclosure statement

The authors confirm that this manuscript has not been published elsewhere and is not under consideration by another journal. All authors have approved the manuscript and agree with submission to the Food Additives & Contaminant: Part A. No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant numbers 31472250 and 31502136], the National ‘Fu Min Qiang Xian’ Program of China [grant number 2012-745], and the Project of Science & Technology of Anhui province [grant number 12010402c206].