A biosensor to detect penicillin residues in food

Avoidance of antibiotic residues is an essential element in the production of safe meat and dairy products. Our objectives in this research were to develop an enzyme immunoassay for beta-lactam penicillins, design an automated sensor to implement this assay, and evaluate the detection performance. An antibody capture with antigen competition assay was developed to run in polystyrene cuvets, with a test time of 13-15 min. A photometric sensor consisting of an optical head, electronic/fluidic board, and control computer was then designed to implement this assay. Results from manual assay tests on ampicillin in phosphate-buffered saline showed a slight reduction in optical density at 100 ng/mL and a significant reduction of 21% for 200 ng/mL. Sensor calibration tests gave similar results, indicating that the detection chemistry was successfully automated Higher affinity or avidity antibodies are needed to detect U.S. and European Community residue limits.