Multiplexed immunoassays by flow cytometry for detection of clenbuterol, chloramphenicol and sulfadimidine with high sensitivity and selectivity

An accurate, rapid and cost-effective detection on the environmental hazardous chemicals is the cornerstone of efficient food safe management. Here we discuss the relevance of an emerging technology, multiplexed competitive immunoassays read by flow cytometry, for the detection of Clenbuterol, Chloramphenicol and sulfadimidine. In these assays, multiple fluorescent microspheres, conjugated to different test antigens, constitute the solid phase for detecting antigens in biological samples based on the competitive ELISA principle. These assays are more sensitive than traditional immunoassays , have a high throughput capacity provide a wide analytical dynamic range and are powerful tools for exposure analysis and assessment offering low-cost screening with minimal sample pretreatment requirements combined and served a better alternative for the instrumental detection on the derivatives of those metabolites that often require expensive instrumentation. The sensitivity for the detection limit of the simultaneous identification of clenbuterol, chloramphenicol and sulfadimidine can reach 0.5ng, 2.0ng and 0.5ng/mL, which shows the promising multiplexing ability. Therefore, we predict a widespread application for a new breed of small, affordable, practical flow cytometrics as field instruments for replacing conventional ELISA and sophisticated GC or HPLC analysis.