Studies on preparation and characterization of Lomefloxacin artificial antigen

An icELISA immunoassay for determination of Lomefloxacin (LOM) residue has been developed. For this purpose, NHS ester technology was employed to synthesize the immunogen and coating antigen of LOM. Infrared spectra and SDS-PAGE identification showed that the artificial antigen was conjugated successfully. Based on the square matrix titration, an icELISA method was established. The dynamic range in assay buffer was from 0.06 to 98.6 ng/mL, with LOD and IC₅₀ value of 0.04 ng/mL and 1.8 ng/mL, respectively. Except for a little cross-reactivity (6.2%) to Ciprofloxacin, this assay showed negligible cross-reactivity to other FQs tested. When spiked in milk, the regression equation was y = 0.9357 × + 0.1333, with a correlation coefficient (R²) of 0.9942. The results suggest that the artificial antigen was synthesized successfully, and the established immunoassay could be used for detecting of Lomefloxacin residues in food samples.