Ultrasensitive immunochromatographic strip for fast screening of piperacillin in milk based on a monoclonal antibody

We developed a lateral flow immunoassay (LFIA) based on a sensitive and specific monoclonal antibody against piperacillin (PIP) with a half-maximal inhibitory concentration of 0.136 ng/mL for PIP detection in milk and milk powder. After the conditions were optimized, the visual limit of detection of LFIA was 2 ng/mL and 5 ng/g, and the cut-off value was 5 ng/mL and 20 ng/g in milk and milk powder, respectively. In the recovery assay of the spiked samples, the results of the LFIA strips were obtained within 10 min and were consistent with those obtained from indirect competitive enzyme-linked immunosorbent assay (ic-ELISA). Therefore, our developed method is a rapid, sensitive, and reliable tool for the detection of PIP in milk and milk powder.