Biotin-labelled peptidomimetic for competitive time-resolved fluoroimmunoassay of benzothiostrobin

In recent years, more and more functional peptide ligands have been identified from phage display libraries and served the immunoassay of small molecules. After the identification, the phage particle instead limits further application of peptide ligands, so it is of great significance to explore the peptide ligand as an independent detection reagent. In this work, the identified peptidomimetic of benzothiostrobin was synthesized and labelled with biotin, which was combined with Eu3+-labelled streptavidin to develop the peptide-based time-resolved fluoroimmunoassay (P-TRFIA). Under the optimal conditions, the half-maximum inhibitory concentration (IC50) of proposed P-TRFIA is 3.63 ng mL(-1), which is similar to the TRFIA using phage-borne peptidomimetic and Eu-3(+)-labelled anti-phage antibody (IC50: 4.55 ng mL(-1)), also more sensitive than previously reported immunoassays for benzothiostrobin. In addition, the proposed P-TRFIA shows excellent specificity and accuracy for analysis of spiked samples, and its detection results shows good consistency with high-performance liquid chromatography for the detection of environment and agro-products samples with unknown benzothiostrobin concentrations.

Automated summary

In this study, a peptide-based time-resolved fluoroimmunoassay (P-TRFIA) was developed with high sensitivity and specificity for detecting benzothiostrobin in environmental and agro-products samples. The method is more accurate than previous immunoassays and shows consistent results with high-performance liquid chromatography.