A liposome immune lysis assay for enrofloxacin in carp and chicken muscle

A homogenous complement-mediated liposome immune lysis assay (LILA) was developed for the determination of enrofloxacin (ENRO) in carp and chicken muscle. ENRO was covalently coupled to DPPE, and then immobilized onto the surface of liposomes by reverse-phase evaporation method. The performed liposome would be specifically lysed by the sequential additions of anti-ENRO monoclonal antibody (MAb) and guinea pig complement. Through a competitive assay format, the performed liposome can be used to detect ENRO in a range of 5.0-20 ng mL⁻¹ in assay buffer. The limit of detection of ENRO in carp and chicken muscle was 1 ng g⁻¹ and the limit of quantification was 2 ng g⁻¹. Recoveries ranged from 58.3% to 65.2% for carp and 55.6-63.8% for chicken muscle at spiked levels of 2-8 ng g⁻¹, with intra-assay and inter-assay variations 5.6-12.3% and 7.1-19.2%, respectively.