Research on Rapid Detection Technology for β 2 -Agonists: Multi-Residue Fluorescence Immunochromatography Based on Dimeric Artificial Antigen.

To detect two types of β 2 -agonist residues at the same time, we coupled two haptens of clenbuterol (CLE) and ractopamine (RAC) to the same carrier protein through diazotization to prepare dimeric artificial antigen, and a fluorescent lateral flow immunoassay method based on europium nanoparticles (EuNP-FLFIA) was established by combining polyclonal antibodies with europium nanoparticles to form probes. Under optimized conditions, the EuNP-FLFIA could simultaneously detect eight aniline-type and one phenol-type β 2 -agonists, and the limits of detection (LOD) were 0.11-0.19 ng/mL and 0.12 ng/mL, respectively. The recovery rate of this method was 84.00-114.00%. This method was verified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the test results were consistent (R 2 > 0.98). Therefore, the method established in this study could be used as a high-throughput screening for the efficient and sensitive detection of β 2 -agonists in food.