Development of a sensitive fluorescent immunoassay based on fluorescent nanoparticles labeling for the quantitation of fipronil in edible flowers

Abstract

Edible flowers have long been used for tea, functional foods, and spices, however, during planting, these natural products are vulnerable to pests and fungal diseases. In recent years, the presence of pesticide residues in edible flowers has attracted extensive attention and of the pesticides found in these products, fipronil residue has been widely reported. Therefore, it is imperative to develop a simple, sensitive, and reliable method for detecting fipronil in edible flowers. In this study, a novel labeled antibody was synthesized by using fluorescent nanoparticles as a secondary antibody, and a fluorescence immunoassay method was established with the conjugated conjugate. The limits of detection and half maximal inhibitory concentration of this method were 0.21 μg/L and 8.61 μg/L, respectively. Furthermore, the developed method was 3.5 times more sensitive than the enzyme-linked immunosorbent assay. After verification, the established method was successfully applied to determine fipronil levels in edible flower samples, and then validated with a gas chromatography-tandem mass spectrometry method. To our knowledge, this is the first report on the successful application of fluorescent nanoparticles in the detection of fipronil in edible flowers.