Biosensor immunoassay for the detection of eight sulfonamides in chicken serum Original Research Article

A monoclonal antibody (MAb) raised against sulfamethazine (21C7) was applied in an optical biosensor (Biacore Q) to develop a rapid biosensor immunoassay (BIA) for the detection of several sulfonamides in chicken serum. The performance of this MAb was compared with two polyclonal antibodies (PAbs) raised against sulfamethazine (Qflex sulfamethazine binding protein (SBP) and RIKILT 464b). Using these PAbs, the limits of detection (LODs) in 10 times diluted chicken serum were approximately 30 ng ml−1 and the two BIAs were found to be specific for sulfamethazine. Using MAb 21C7, the LOD for sulfamethazine in 10 times diluted chicken serum was lower (10 ng ml−1), high cross-reactivities were measured for sulfisoxazole (149%), sulfachlorpyridazine (112%), sulfachlorpyrazine (94%), sulfamerazine (87%), sulfadiazine (56%), sulfatroxazole (56%) and sulfathiazole (50%) and low cross-reactivities (11–25%) were measured with six other sulfonamides. Compared with the polyclonal antibodies, the MAb-based BIA resulted in a better sensitivity and was found suitable for the detection of 8 sulfonamides in 10 times diluted chicken serum with LODs between 7 and 20 ng ml−1. The total run time for each cycle was 7 min.