A sensitive chromatographic strip test for the rapid detection of enrofloxacin in chicken muscle

Abstract A sensitive colloidal gold immunochromatography assay using a specific monoclonal antibody was developed for the rapid detection of enrofloxacin (ENR) residues in chicken muscles. Anti‐ENR antibodies with high sensitivity and specificity are generated by immunising BALB/c mice with well‐characterised ENR‐bovine serum albumin conjugate. An orthogonal L9(3)3 test was designed, and various parameters that influenced the assay performance were investigated and optimised. Under the optimised conditions, the cut‐off limits of semi‐quantitative test strips for ENR were found to be 3 ng/mL in phosphate‐buffered saline and 8 µg/kg in chicken muscle. The ENR test strips showed a 6% cross‐reactivity with ciprofloxacin, 3% with norfloxacin, less than 1% with ofloxacin and sarafloxacin and 0.1% with the other eight fluoroquinolones including enoxacin, difloxacin, danofloxacin, pefloxacin, lomefloxacin, sparfloxacin, oxolinic acid and flumequine. Consistent results are produced from the parallel analysis of ENR‐contaminated chicken muscle extracts using test strips and ELISA. Keywords: enrofloxacinmonoclonal antibodycolloidal goldimmunochromatography assaytest strip Acknowledgements The authors are thankful for the financial support from the National 863 Program of China (No. 2007AA10Z438) and industry‐university cooperation Program of Jiangxi province of China (No. GJJJ10009). Notes These authors contributed equally to this work. Additional informationNotes on contributorsHengyi Xu These authors contributed equally to this work.