In recent years, due to the unscientific and irrational use of bacitracin (BAC), the drug resistance of animal-derived bacteria has continued to increase, posing a threat to animal-derived food safety and public health safety. Therefore, there is an urgent need to develop a rapid and sensitive BAC assay. In this study, BAC-ovalbumin was used as the coated antigen, mouse monoclonal antibody was used as the detection antibody, and the working system was optimized. An indirect competitive chemiluminescent enzyme immunoassay (ic-CLEIA) for the detection of BAC was established. Under the optimal conditions, the half maximal inhibitory concentration of the method was 0.10 ng/mL, and the linear range of detection was 0.05–2.19 ng/mL. Limit of detection of the method was at least 500 times lower than the maximum residue limits. The sample spike recovery experiment revealed that the recovery rates for animal tissue and milk were 78.7 %–93.7 % and 81.3 %–96.7 %, respectively. The intra-assay and interassay coefficients of variation were all less than 15 %, with good precision and no cross-reaction with five bacitracin analogs. At the same time, HPLC also verified the reliability of the method. This method provides a convenient, accurate and rapid means of screening BAC residues in actual animal-derived foods.
Prothioconazole and its metabolite are considered a potential threat to human health and environmental safety. Thus, the development of a sensitive and rapid detection method for prothioconazole is crucial to ensure the safety of agricultural products. In this study, a new hapten of prothioconazole was designed and synthesized, and a selective polyclonal antibody with high affinity against prothioconazole was produced, which was obtained from immunized New Zealand white rabbits. Based on the polyclonal antibody, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) were developed for detecting prothioconazole pesticides. Under optimized experimental conditions, the limit of quantification (LOQ) values for ic-CLEIA and ic-ELISA were 1.8 and 10.7 ng mL−1, respectively. The results demonstrated that the sensitivity (LOQ) achieved by ic-CLEIA was more than five times higher compared to that obtained with ic-ELISA. In addition, the recoveries obtained by adding standard prothioconazole to wheat grain, soybean, and pond water samples were in the range of 81.9 to 104.7% for ic-ELISA and 89.0 to 118.0% for ic-CLEIA.
危险品化学品经营许可证（带存储）