Rhodium nanocatalyst-based lateral flow immunoassay for sensitive detection of staphylococcal enterotoxin B

Compared with traditional laboratory-based tests, lateral flow immunoassay (LFA) has been developed as one of the emergent and popularly used rapid detection technology. Due to unique physical and chemical properties, novel nanomaterials have been widely used as the signal label in LFA for the detection of analytes, but these assays merit further development to improve sensitivity. Here, we developed a rhodium (Rh) nanozyme-labeled LFA with high sensitivity for paper-based detection of staphylococcal enterotoxin B (SEB), one of the super-antigens that may cause illness. The synthesis and optimization of Rh nanozymes were illustrated, which show excellent peroxidase-like catalytic activity. Harnessing the catalytic amplification of Rh nanozymes enabled naked-eye detection of SEB as low as 1.2 pg·mL-1 in the whole milk sample, which increases 250 folds compared with the commercial ELISA tests. Additionally, the recoveries rate for spiking dairy samples was determined to be 94.3–124.8% for SEB, which indicated the good accuracy and precision of Rh-based LFA. We believe this Rh based LFA for detecting toxins may open new possibilities for similar immunochromatographic testing methods. •Rhodium nanozyme-labeled lateral flow immunoassay (Rh-LFA) was constructed with high sensitivity for the detection of SEB.•The detection limit of Rh-LFA system is almost 250-folds lower than that of the commercial kits for SEB detection.•Established platform can be readily adapted for the detection of other targets and monitoring of food safety.