Comparative analysis of immunization strategies for broad-specificity antibody preparation and immunoassay development for sulfonamides detection in chicken and pork samples

With the widespread use of sulfonamides (SAs) as veterinary drugs, the levels and diversity of residues in food are increasing. Rapid monitoring of SAs with high throughput is essential to ensure food safety and protect human health. Thus, the preparation for broad-specificity antibodies against a class of drugs has garnered considerable attention in recent years. This study systematically investigated the effectiveness of various immunization strategies-single-sulfonamide immunogen, designed-hapten immunogen, and multi-immunogen-using a total of 13 immunogens to prepare broad-specificity monoclonal antibodies (mAbs) targeting 30 SAs. Three mAbs with different broad spectrum were successfully obtained, which could identify up to 25 different types of SAs. Computational simulation and molecular docking revealed that the -SO2NH- moiety was the critical binding site for broad-specificity mAbs. Additionally, the lateral flow immunoassays were developed to detect SAs in chicken and pork samples with the recovery ranging from 86.1% to 105.1% and the coefficient of variation ranging from 2.1% to 10.9%. Overall, this study presents a systematic comparison of immunization strategies for preparing broad-specificity antibodies and provides both theoretical and practical insights into the production of these antibodies using a multi-immunogen approach. It provides a powerful tool for the efficient detection of SAs veterinary drugs in food, thus reinforcing safeguards for food safety.