ABSTRACT
Diminazene (DIM) is widely used to treat trypanosomiasis in livestock, but its residues in animal products can cause food safety problems. Thus, a rapid colloidal gold-based immunochromatographic strip assay was established to analyse DIM residue in milk samples. A highly sensitive and specific monoclonal antibody (mAb) against DIM was produced with a new synthetic immunogen by the active ester method. The titre of the prepared antibody was up to 1:1.0 × 106, the affinity constant was 2.2 × 108 L mol−1 and the half-maximal inhibitory concentration (IC50) was 0.4 ng mL−1 based on enzyme-linked immunosorbent assay (ELISA). Then, the colloidal gold-labelled mAb probe was successfully prepared and used for preparing the immunochromatographic strip. The strip showed high sensitivity and specificity, the IC50 for DIM was 5.2 ng mL−1, the limit of detection was 1.2 ng mL−1 and the linear range of detection was 1.8–15.4 ng mL−1. The average recoveries ranged from 89.5% to 91.7%, and coefficients of variation were 6.6–7.2%. The immunochromatographic strip assay can be employed in the rapid detection of DIM residue in milk samples.
Graphical Abstract
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Disclosure statement
No conflict of interest was declared by the authors.