Rapid and sensitive detection of haloxyfop-P-methyl by competitive and noncompetitive immunoassays using phage-displayed peptides
Haloxyfop-P-methyl, a widely used aryloxyphenoxypropionate herbicide, has been identified as a potential hazard to ecological security and human health. Consequently, it is essential to develop superior methods for detecting haloxyfop-P-methyl. In this study, 12 peptidomimetics and 4 anti-immunocomplex peptides were isolated from phage-displayed peptide libraries, which can specifically recognize the anti-haloxyfop-P-methyl antibody and the immunocomplex formed by haloxyfop-P-methyl and its antibody, respectively. Following the sensitivity assessment of each phage-displayed peptide, competitive and noncompetitive phage enzyme-linked immunosorbent assays (P-ELISAs) were developed using the best phage-displayed peptides. The half inhibition concentration (IC 50 ) and half saturation concentration (SC 50 ) of competitive and noncompetitive P-ELISAs were determined to be 8.15 and 1.83 ng/mL, respectively, representing the 5-fold and 22-fold increase in sensitivity compared to previously reported immunoassay. The competitive P-ELISA exhibited 2.2%–114.8% cross-reactivities (CRs) to haloxyfop-methyl, haloxyfop and quizalofop-p-ethyl, while the noncompetitive P-ELISA showed no significant CR (<0.1%) except for haloxyfop-methyl (CR = 41.6%). The average recoveries of two P-ELISAs in soil, soybean, potato, and cabbage samples ranged from 78.4% to 104.3% and 76.8%–95.2%, respectively. Additionally, the results of P-ELISAs for blind samples exhibited a good correlation with those obtained from ultra-performance liquid chromatography/tandem mass spectrometry.
危险品化学品经营许可证（带存储）