Ultrasensitive immunochromatographic strips for fast screening of the nicarbazin marker in chicken breast and liver samples based on monoclonal antibodies

Abstract

Nicarbazin is an anticoccidial drug with a residue limit in animal husbandry. 4,4′-Dinitrocarbanilide (DNC) is the residue marker of nicarbazin. In this research, designed and based on new haptens, a sensitive and specific monoclonal antibody was produced against DNC. The IC₅₀ value of the prepared mAb 3A3 was 0.14 ng mL⁻¹ and the LOD was 0.02 ng mL⁻¹. The recovery rate of the chicken breast and liver samples were 93.50–115.60% and 99.60–108.00%, respectively. The results of the cross-reaction experiment show that it is highly specific for DNC. A colloidal gold immunochromatographic test strip was prepared for rapid detection of DNC in the chicken breast and liver samples. The visual limits (LODs) of DNC detection in the chicken breast and liver samples were 2.5 μg kg⁻¹ and 5 μg kg⁻¹, and the cut-offs were 10 μg kg⁻¹ and 10 μg kg⁻¹, respectively. Therefore, the preparation of colloidal gold immunochromatographic test strips can be meaningful for the on-site detection and rapid screening of numerous samples.