Streptavidin-biotin system-mediated immobilization of a bivalent nanobody onto magnetosomes for separation and analysis of 3-phenoxybenzoic acid in urine

) were analyzed. The quantitative recoveries ranged from 82.5% to 113.1%, which agreed well with the findings obtained using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Overall, the BMP-SA-Biotin-Nb2-based immunoassay holds great promise for rapid monitoring of 3-PBA following acid dissociation.