The heterologous strategy could improve the sensitivity of competitive enzyme-linked immunosorbent assay (ELISA) for detection of chemical contaminants in food samples. In this study, the heterologous coating antigen ELISA was developed to evaluate its sensitivity for mebendazole (MBZ). Results showed that the heterologous ELISA had a linear range of (IC20-IC80) 0.34-10.54 ng/mL, an IC50 value of 1.83 ng/mL, and a limit of detection (LOD) of 0.13 ng/mL, in which the sensitivity of ELISA improved 1.7- and 2-fold (IC50 value dropping from 7.41 and 3.65 ng/mL to 4.27 and 1.83 ng/mL) than that of rabbit IgG- and chicken IgY-based homologous ELISA for MBZ, respectively. The heterologous coating antigen ELISA showed negligible cross reactivity (<0.2%) with its structural analogues, including hydroxy-MBZ, albendazole, oxfendazole, fenbendazole, and flubendazole, except the value of 72.6% for amino-MBZ. The average recoveries of MBZ spiked in pork and chicken muscle samples by the assay ranged from 83.7% to 109.8% and agreed well with those of high-performance liquid chromatography. The results suggested that using heterologous coating antigen could distinctly improve the sensitivity of ELISA for routine screening of MBZ residues in food samples.
Keywords: Heterologous coating antigen; amino-mebendazole; chicken IgY; mebendazole; rabbit IgG.