Immunochromatographic method based on PCN-222 with dual-signal output for the rapid and sensitive detection of furazolidone metabolites in animal-derived food

The residues of furazolidone and its metabolites (3-amino-2-oxazolidinone [AOZ]) in food would have adverse effects on humans. Herein, a colorimetric and fluorescent dual-signal output immunochromatographic method with a zirconium-based porphyrin metal-organic framework (PCN-222) as the signal label was developed for the detection of 3-[(4-carboxyphenyl) monomethyl] amino-2-oxazolidinone (CPAOZ), a derivative of furazolidone metabolite. PCN-222 was synthesized using the solvothermal method, and the material was characterized via scanning electron microscopy, Fourier-transform-infrared spectroscopy, and powder X-ray diffraction, which proved the successful synthesis of PCN-222. Synthesized PCN-222, as a nanotag, was bound to antibodies to prepare PCN-222-mAbs with dual optical properties. Under the optimized conditions, PCN-222- lateral flow assay (LFA) exhibited a great linear relationship in the range of 0.25–100 ng/mL. The visual limit detection of CPAOZ using colorimetric and fluorescent signals were 1.0 ng/mL and 0.5 ng/mL, respectively, and the sensitivity was 5- and 10-fold higher than that of the colloidal gold-based LFA method. In addition, PCN-222-LFA was successfully applied to the detection of CPAOZ in shrimp, chicken and milk samples achieving satisfactory recoveries from 92.34% to 117.44%. This study provides an alternative, convenient and sensitive method for the rapid detection of veterinary drug residues.