Immunochromatographic assays for ultrasensitive and high specific determination of enrofloxacin in milk, eggs, honey, and chicken meat

Abstract

Enrofloxacin, a veterinary antibiotic that persists in food, poses a risk to human health. Here, a monoclonal antibody against enrofloxacin, 1H12, was prepared based on the hapten ENR-1, and showed excellent sensitivity with a 50% inhibitory concentration (IC 50 ) of 0.03 ng/mL. Using this antibody, 2 lateralflow immunochromatographic assays were developed for determination of enrofloxacin in egg, milk, honey, and chicken samples. The detection ranges (IC 20 -IC 80 ) were 0.16-0.82 ng/g, 0.24-1.8 ng/g, 0.25-3.6 ng/g, and 0.61-3.9 ng/g by colloidal gold-immunochromatographic sensor (CG-ICS) analysis, and 0.022-0.42 ng/g, 0.054-0.42 ng/g, 0.069-1.4 ng/g, and 0.19-2.2 ng/g by Eu-fluorescence-immunochromatographic sensor (EF-ICS) analysis. The intraassay and interassay recovery rates were 88.9 to 108.5% with coefficients of variation of 1.3 to 7.0% by CG-ICS analysis, and 88.6 to 113.6% with coefficients of variation of 1.3 to 8.1% by EF-ICS analysis. Thus, our newly developed ICS are sensitive and reliable, providing an option for rapid quantitative detection of enrofloxacin in food samples.

Electrochemical detection of enrofloxacin in meat using bimetallic organic framework-derived NiCo2O4@NiO

“…So far, many techniques have been developed to detect ENR residues, including immunochromatographic assays, 18 high-performance liquid chromatography coupled to fast-scanning fluorescence detection, 19 surface-enhanced Raman scattering, 20 capillary-tube indicators, 21 colorimetric screening 22 and electrochemical sensing. 23 However, the disadvantages of expensive equipment, specialized detectors and techniques have limited the application of these methods.…”

Fluorescent strip sensor for rapid and ultrasensitive determination of fluoroquinolones in fish and milk

“…Immunogens were prepared by combining Nor-1 (M w = 405.7) with carrier proteins using the activated ester method. 31,32 In brief, Nor-1 (9 mg), NHS (7.7 mg) and EDC•HCl (12.7 mg) were dissolved in N,N-dimethylformamide (DMF, 0.7 mL), N,N-dimethylformamide (DMF, 0.1 mL) and 4-morpholineethanesulfonic acid solution (MES, 0.1 M, 0.1 mL), respectively. Then, the EDC•HCl solution and the NHS solution were added dropwise into the Nor-1 solution at RT, and the mixture was allowed to react for 4 h under constant stirring.…”

“…Female BALB/c mice (6-8 weeks of age) were used for immunization with the antigen Nor-1-BSA, following the method and procedure of immunization referred to in previous studies. 31,34 After the fourth booster immunization, a small amount of blood was collected from the tail of each mouse and tested using indirect competitive enzyme-linked immunosorbent assay (ic-ELISA). OD 450 nm values in PBS solution and inhibition ratio of standard solutions were used to evaluate the immune effect of the mice, which reflect the affinity of the antibody in sera to coating antigen and target standards, respectively.…”

“…Eu-fluorescent microspheres (EFMs) that had been modified with carboxyl groups were conjugated to the mAb by the amidation reaction, as previously described. 31,39 In brief, 100 µL of EFMs were diluted with 400 µL of borate buffer (BB, 0.05 M, pH 8.0), and then the EFM solution was mixed with 30 µL of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride solution (10 mg mL −1 ) for 15 min at RT. The solution was centrifuged at 12 000g for 10 min, then the sediment was re-dissolved in BB solution with ultrasonic treatment (100 W, 1 min).…”

Gold nanoparticle-based lateral flow immunoassay for the rapid detection of flumetralin in orange

“…To evaluate the performance of the LFIA strip, we serially diluted the analyte standard in PBS to assess the cut-off value and visual limit of detection (vLOD). [38][39][40] We defined the cut- off value as the flumetralin concentration at which the color of the T line completely disappeared and vLOD as the lowest concentration at which the color of the T line is weaker than that of the C line. However, we found that the cut-off value was difficult to measure because the background derived from the coating antigen cannot be completely excluded.…”