The Simultaneous Detection of Multiple Antibiotics in Milk and Pork Based on an Antibody Chip Biosensor

In the modern farming industry, the irrational or illegal use of veterinary drugs leads to residues in animal-derived food, which can seriously threaten human health. Efficient detection of low concentrations of drug residues in animal products in a short time is a key challenge for analytical methods. This study proposes to use an antibody chip biosensor for rapid and automated analysis of cephalosporins, aminoglycosides, and sulfonamide antibiotics in pork and milk. 3D polymer slides were applied for the preparation of antibody chips. Ovalbumin (OVA) or bovine serum albumin (BSA) conjugates of the haptens were immobilized as spots on disposable chips. Monoclonal antibodies (mAbs) against cefalexin, ceftiofur, gentamicin, neomycin, and sulfonamides allowed the simultaneous detection of the respective analytes. Antibody binding was detected by a second antibody labeled with Cy3-generating fluorescence, which was scanned a with chip scanner. The limits of detection (LOD) for all the analytes were far below the respective maximum residue limits (MRLs) and ranged from 0.51 to 4.3 µg/kg. The average recoveries of all the analytes in each sample were in the range of 81.6-113.6%. The intra- and inter-assay CV was less than 12.9% and showed good accuracy and precision for all the antibiotics at the MRL level. The sample pretreatment method is simple, and the results are confirmed to be accurate by LC-MS/MS; therefore, this method is valuable for the quality control of animal-derived food.