Application of boron-dipyrromethene-labeled erythromycin for macrolide detection with fluorescence polarization immunoassay

Immune assays are widely used in various fields of medicine, including enzyme-linked immunosorbent assays, fluorescence polarization immunoassay (FPIA), and immunochromatographic analysis. FPIA allows for high specificity and sensitivity detection of low-molecular-weight analytes in a homogeneous medium without separation; it has high accuracy and label stability, and analysis is fast, simple, and can be automated. A fluorescently labeled tracer for erythromycin determination with a new boron-dipyrromethene (BODIPY) dye was developed in this study. A pair of immunoreagents (tracers and antibodies) for detecting erythromycin was selected and characterized, and FPIA conditions were optimized for an analysis time of 5 min. Calibration curves were obtained, and FPIA analytical characteristics were determined. The limit of detection was 1.6 ng/mL with a detection range at pH 7.4 of 5 − 300 ng/mL. The developed FPIA was successfully used to determine erythromycin concentration in water and milk, with a recovery of 80% – 120%. Overall, an FPIA method for erythromycin determination was developed, the advantages of using the new BODIPY fluorescent label were shown, the accuracy of the method was verified by an recovery test, and real water samples were tested.