Development of immunoassays based on specific monoclonal antibody for sensitive detection of azoxystrobin residues

Azoxystrobin (AZX) is a widely used fungicide for the prevention and management of agricultural diseases, but its adverse effects on non-target organisms have raised concerns. In this study, monoclonal antibodies (mAbs) against AZX were developed to establish an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and a colloidal gold immunochromatographic assay (GICA) for AZX detection. Eight hybridoma cell lines capable of stably secreting anti-AZX mAbs were prepared, among which the mAb 2A3C6 with the highest sensitivity was used in the immunoassays. The ic-ELISA showed a half-maximal inhibitory concentration (IC 50 ) of 0.61 μg L −1 , and the GICA demonstrated a visual limit of detection (vLOD) of 0.6 μg L −1 . Both assays demonstrated high specificity, with no cross-reactivity observed for AZX analogues. Spiked recovery and blind sample detection confirmed the excellent sensitivity and reliability of these immunoassays for detecting AZX in environmental and agricultural samples.