Development of an immunochromatography strip for the rapid detection of 12 fluoroquinolones in chicken muscle and liver.

A rapid and sensitive colloidal gold immunochromatography test strip based on one monoclonal antibody with broad-specificity, which can detect 12 fluoroquinolones (FQs), was developed. Antigen and goat anti-mouse IgG were respectively drawn on NC membrane as test line and control line. Gold-labeled antibody was added on a pad and put on one end of the membrane. Fluoroquinolones in sample solution compete with antigen combined on NC membrane for the gold-labeled antibody. When enough fluoroquinolone exists, the test line vanishes as there are no spare gold-labeled antibodies that can bind with antigen on the membrane. The control line always exists when the antibody is activated. The lowest detection limits of the FQs in spiked chicken muscle and chicken liver samples were 25 ng mL(-1) for norfloxacin and pefloxacin. The lowest detection limit for the other 10 FQs (enrofloxacin, ciprofloxacin, norfloxacin, flumequine, pefloxacin, ofloxacin, lomefloxacin, enoxacin, danofloxacin, amifloxacin, oxolinic acid, and marbofloxacin) was 50 ng mL(-1). The whole process involving sample preparation and detection can be finished in <10 min. The results demonstrate that the developed method can be potentially used as a screening tool for the determination of 12 FQ residues in a large amount of samples on site.