A highly specific and sensitive fluorescence polarization immunoassay for the rapid detection of triazophos residue in agricultural products

Abstract

A rapid, homogeneous, and high-throughput fluorescence polarization immunoassay (FPIA) was developed. The established assay was based on a specific anti-triazophos monoclonal antibody (mAb) and two different fluorescent tracers (THBu-AMF & THBu-EDF), which were synthesized and characterized in this work. After optimization and comparison, THBu-EDF and anti-triazophos mAb were used to construct the FPIA method for triazophos detection. The reaction time, less than 10 min, obviously highlighted the special feature of FPIA. The limit of detection was 0.29 μg L⁻¹ and the half maximal inhibitory concentration (IC₅₀) was 3.62 μg L⁻¹. The developed method showed no evident cross-reactivities with other organophosphorus pesticides. The accuracy and precision of the developed FPIA were further evaluated. Results showed that the average recoveries from spiked water, brown rice, cabbage and apple samples ranged from 72.07% to 104.35%, with coefficients of variation from 3.09% to 16.99% for the intra-day test and from 3.11% to 17.51% for the inter-day test. Moreover, the FPIA displayed comparable reliability and high correlation with gas chromatography (R² ≥ 0.9680). Our data clearly manifested that the proposed FPIA was fit for rapid screening of triazophos residues in agricultural products.