Immunological quantitative detection of dicofol in medicinal materials

Abstract

In this study, a highly specific and sensitive monoclonal antibody against dicofol (DIC) was prepared and used to create a colloidal gold immunochromatographic strip (ICS) for the quantitative analysis of DIC in liquorice and Angelica sinensis samples. We found that for both the liquorice and Angelica sinensis samples, the cut-off value for the ICS was 500 ng g⁻¹, respectively, and using a colloidal gold test strip reader, the half-maximal inhibitory concentrations (IC₅₀) were found to be 35 ng g⁻¹ and 88 ng g⁻¹, the limits of detection were 2 ng g⁻¹ and 3 ng g⁻¹, and the linear detection scopes (IC₂₀–IC₈₀) were from 6 to 201 ng g⁻¹ and from 10 to 819 ng g⁻¹, respectively. In the recovery test, we found that recoveries were within the range of 90.6% to 97.2% and the coefficients of variation were less than 8.6% in the intra-assay and inter-assay for the liquorice samples and the recoveries ranged from 90.8% to 97.3% and the coefficients of variation were less than 9.1% in the intra-assay and inter-assay for the Angelica sinensis samples. The established ICS assay could be used for the rapid quantitative screening of chemicals in Chinese traditional medicinal materials.