Colloidal Carbon-labelled Immunochromatographic Assay for Rapid Detection of Marbofloxacin Residues in Animal-derived Foods

Abstract:

[Objective] A colloidal carbon-labelled immunochromatographic assay with competitive inhibition was developed for the detection of marbofloxacin (MBF) residues in milk powder and chicken.[Method] The anti-MBF polyclonal antibody prepared in the author's laboratory was employed to produce the colloidal carbon-labelled immunoprobe. The effects of pH of reaction system, resuspension solution, treatment solution of sample pad, standard dilution buffer, mass concentration of colloidal carbon, mass concentration of primary antibody, mass concentration of coating antigen, and mass concentration of secondary antibody on the MBF colloidal carbon-labelled immunochromatographic assay were investigated. The sensitivity, specificity, stability, and accuracy of the method were determined.[Result] Under optimal conditions, the cut-off value of the method was 4.0 ng/mL,which was five times higher than the value of traditional colloidal gold-labelled immunochromatographic assay. The semi-quantitative detection limit was 0.4 ng/mL. The method showed good specificity for the detection of MBF and could be stored at room temperature for 16 weeks. The spiked recovery results in milk powder and chicken samples were basically consistent with those of ultra-high performance liquid chromatography coupled with a fluorescence detector.[Conclusion] The established method is simple, sensitive, specific, and stable, and thus it can be utilized for rapid detection of MBF residues in animal-derived foods.