Biosensor immunoassay for the detection of eight sulfonamides in chicken serum

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 BlAs were found to be specific for sulfamethazine. Using MAb 210, 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. (C) 2002 Elsevier Science B.V. All rights reserved.