Development of a Highly Sensitive Time-Resolved Fluorescence Immunochromatographic Assay for Rapid Onsite Determination of Prometryn Residues in Food Samples

Prometryn, a triazine herbicide used for weed control, poses a significant risk to aquatic organisms in the environment. Herein, a recombinant full-length antibody against prometryn (PRO-rAb) was conjugated with europium microspheres to serve as a detection probe for the development of a time-resolved fluorescence immunochromatographic assay (TRFICA) to detect prometryn residues in various agricultural samples, such as corn, pumpkin, lotus root, rice, and brown rice. The method demonstrated a maximum half-inhibition concentration (IC50) of 1.1 ng/mL, a linear range of 0.25–11.7 ng/mL, and substantial recovery from 85% to 106%. Strong correlations (R2 = 0.98) between the results of established TRFICA and ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) indicated that the established fluoroimmunoassay has great potential in food safety monitoring. This consistency indicated the suitability of both methods for detecting prometryn in five different agricultural samples, suggesting that it is a convenient and practical approach for screening prometryn in agricultural products.