Fluorescence immunoassay for the targeted determination of trace based on immunomagnetic separation and CdZnTe quantum dot indication.

Infections from invasive () frequently occur in food and can cause high morbidity and death. Thus, the sensitive, specific, and rapid detection of is critical for ensuring food safety and public health. Herein, a fluorescence immunoassay for trace detection was designed based on guinea pig antibody-functionalized magnetic nanoparticles (FeO NPs/pAb1) and rabbit antibody-anchored CdZnTe quantum dots (CdZnTe QDs/pAb2). Because of the antibody-directed magnetic separation and long-wave fluorescent emission for CdZnTe QD indication, the constructed immunoassay strategy presented excellent anti-interference performance toward a biological matrix. The immunosensor exhibited a wide detection range of 1 to 10 CFU mL for and a low limit of detection (LOD) of 1 CFU mL, achieving an exceptionally sensitive detection of trace . Meanwhile, the immunosensor showed good specificity and had a short time-consumption of 60 min to realize the accurate determination of trace in spiked tap water and pasteurized milk samples.