Monoclonal Antibody-Based Colorimetric Lateral Flow Immunoassay for the Detection of Pyridaben in the Environment

Pyridaben inhibits cell cycle progression and delays early embryonic development in zebrafish (Danio rerio)

Pyridaben is a broad-spectrum, contact-killing acaricide that can be used to control a variety of harmful food and plant mites. Pyridaben displays cardiotoxicity and liver toxicity toward fish, but the effects on fish embryonic development have not been characterized. We exposed early zebrafish embryos to 20, 30, and 40 μg/L concentrations of pyridaben. The exposure caused developmental abnormalities, including delayed embryonic shield formation, yolk sac resorption, decreases in body length, reduced pigmentation, and delays in hatching. Pyridaben caused a significant increase in the transcription level of the endoderm marker foxa2, but the transcription levels of the ectoderm development marker foxb1a and the mesoderm development marker snaila were not significantly altered. The transcription levels of the genes SOX17 in early embryos were significantly reduced. After exposure to pyridaben, catalase (CAT) activity and glutathione (GSH) content were increased, and cyclin D1, that is involved in early embryonic development, was abnormally expressed. This study shows that pyridaben causes anomalous development in zebrafish embryos by interfering with the cell cycle order of early embryonic development and inducing excessive oxidative stress. Colivelin, an agonist of the STAT3 signaling pathway, acted as a salvage drug to restore the cell cycle order during embryonic development following exposure to pyridaben. Thus, the toxic effects may be caused by pyridaben's regulation of the STAT3 signaling pathway.

Quantitative determination of prothioconazole in wheat grain, soybean, and pond water based on a polyclonal antibody

Prothioconazole and its metabolite are considered a potential threat to human health and environmental safety. Thus, the development of a sensitive and rapid detection method for prothioconazole is crucial to ensure the safety of agricultural products. In this study, a new hapten of prothioconazole was designed and synthesized, and a selective polyclonal antibody with high affinity against prothioconazole was produced, which was obtained from immunized New Zealand white rabbits. Based on the polyclonal antibody, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) were developed for detecting prothioconazole pesticides. Under optimized experimental conditions, the limit of quantification (LOQ) values for ic-CLEIA and ic-ELISA were 1.8 and 10.7 ng mL-1, respectively. The results demonstrated that the sensitivity (LOQ) achieved by ic-CLEIA was more than five times higher compared to that obtained with ic-ELISA. In addition, the recoveries obtained by adding standard prothioconazole to wheat grain, soybean, and pond water samples were in the range of 81.9 to 104.7% for ic-ELISA and 89.0 to 118.0% for ic-CLEIA.

Development of an immunoassay based on a specific antibody for the detection of diphenyl ether herbicide fomesafen

Fomesafen belongs to the diphenyl ether herbicide, and is widely used in the control of broadleaf weeds in crop fields due to its high efficiency and good selectivity. The residual of fomesafen in soil has a toxic effect on subsequent sensitive crops and the microbial community structure because of its long residual period. Therefore, an efficient method for detecting fomesafen is critical to guide the correct and reasonable use of this herbicide. Rapid and sensitive immunoassay methods for fomesafen is unavailable due to the lack of specific antibody. In this study, a specific antibody for fomesafen was generated based on rational design of haptens and a sensitive immunoassay method was established. The half maximal inhibitory concentration (IC50) of the immunoassay was 39 ng/mL with a linear range (IC10-90) of 1.92-779.8 ng/mL. In addition, the developed assay had a good correlation with the standard UPLC-MS/MS both in the spike-recovery studies and in the detection of real soil samples. Overall, the developed indirect competitive enzyme immunoassay reported here is important for detecting and quantifying fomesafen contamination in soil and other environmental samples with good sensitivity and high reproducibility.