A Multiplex Immunochromatographic Assay Employing Colored Latex Beads for Simultaneously Quantitative Detection of Four Nitrofuran Metabolites in Animal-Derived Food

Abstract

A rapid and sensitive high-throughput latex bead immunochromatographic assay (LB-ICA) for simultaneously quantitative detection of four major nitrofuran metabolites, including semicarbazide (SEM), 1-aminohydantoin (AHD), 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ), and 3-amino-2-oxazolidinone (AOZ) in animal-derived food (chicken, fish, and shrimp) was developed. Four different coating antigens were separately immobilized on nitrocellulose (NC) membrane as capture reagents; red latex beads were sprayed as constant control line. Specific monoclonal antibodies labeled with blue- or red-colored latex bead reacted with analytes in standard or sample and flowed along the strip, exhibiting visible and colorful test lines after unbound antibodies coupled with corresponding antigens on four test lines. No mutual interference was found in the simultaneous detection of the four analytes even at concentrations (100 μg L−1) higher than their respective cutoff values. The limits of detection (LODs) for SEM, AHD, AMOZ, and AOZ were 0.02–0.1 μg kg−1 in chicken, 0.02–0.15 μg kg−1 in fish, and 0.03–0.12 μg kg−1 in shrimp, respectively. Recoveries ranged from 73.5 to 109.2% at fortified concentration of LOD, 2LOD, and 4LOD, with coefficient of variation < 15%. Analysis of field animal-derived food samples by LB-ICA was in accordance with that of LC-MS/MS. Therefore, this proposed multiplex LB-ICA was a promising method for on-site screening of multiple analytes in animal-derived food.