Immunochemical approaches for detection of aflatoxin B1 in herbal medicines

Introduction Aflatoxin B1 (AFB1) is a toxic low-molecular-weight secondary metabolite ofAspergillus flavusandA. parasiticus.AFB1 was classified as a Group I carcinogen by the World Health Organisation for Research on Cancer in 1993. AFB1 is an unavoidable natural contaminant of some herbal medicine, able to cause serious health issues for humans consuming the related medicine. Objective Therefore, this study aimed to develop an efficient fluorescence polarisation immunoassay (FPIA) and a rapid, low-cost, and easy-to-use membrane-based flow-through immunoassay (MBA) for determination of AFB1 in herbal medicineOriganum vulgareL.,Rubus idaeusL., Urtica dioicaL. andSorbus aucupariaL. Results A cut-off level of the developed MBA was 0.8 ppb. Validation of the developed test was performed with blank and spiked samples. Using three naturally contaminated or three artificially spiked samples. The FPIA showed a linear working range of 8.6 to 64 ppb, and a half maximal inhibitory concentration (IC50) of 24 ppb. Conclusion The results were in good correlation with the enzymelinked immunosorbent assay (ELISA) results (the IC(50)0.1 ppb). Both the sample preparation and analysis are simple, cost-effective and easy to perform on-site in non-laboratory environments. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used as a confirmatory technique.