Imazalil (IMZ) is a generally used fungicide for controlling fungus in agriculture, leaving residual IMZ in crops that may very well be hazardous to human well being. On this work, we designed IMZ haptens for mice immunization and ready delicate monoclonal antibody (mAb) towards IMZ. The subtype of anti-IMZ mAb is IgG2a. It possessed a half inhibition focus (IC₅₀) of 0.95 ng mL⁻¹ and confirmed no cross-reactivity towards different chemical substances in ic-ELISA. Benefiting from the mAb, we developed a gold nanoparticle-based immunochromatographic assay (GICA) for the speedy detection of IMZ in grapes and tomatoes. The assay gave a visible restrict of detection (vLOD) of 25 ng g⁻¹ and cut-off worth of 500 ng g⁻¹ in each samples. Based on the calibration curves, the calculated LOD had been 4.12 ng g⁻¹ and 4.70 ng g⁻¹ in grapes and tomatoes, respectively. The restoration charges of IMZ ranged from 84.7% to 104.4% with variation coefficients (CVs) of 5.7–11.8% in spiked samples, indicating a potent practicability of the GICA. The entire GICA course of took 30 min. Subsequently, the developed assay can be utilized for on-site detection and quantitation of IMZ in grape and tomato samples.