Wei Sheng, Yue Liu; Shijie Li; Yang Lu; Qing Chang; Yan Zhang; Shuo Wang


A quantum-dot-based immunochromatographic assay (QICA) and a fluorescence quenching immunochromatographic assay (FQICA) were developed to visually detect bisphenol A (BPA). The proposed QICA and FQICA were based on traditional immune competition and on fluorescence resonance energy transfer (FRET) from fluorescence donors (quantum dots) to fluorescence acceptors (colloidal gold nanoparticles), respectively. For the QICA, the concentration of the target negatively correlated with the fluorescent signals, whereas this correlation was positive for the FQICA. The visual limits of detection (LOD) of proposed QICA and FQICA were 10 and 4 μg kg−1 (μg L−1) in samples, respectively. Additionally, the results obtained with the two proposed assays agreed well with those obtained by high-performance liquid chromatography (HPLC), indicating the high accuracy of the proposed assays. These two proposed fluorescence immunochromatographic assays can be applied to rapidly, sensitively, and accurately detect BPA in distillate spirits (42%, v/v), cabbage, grass carp, and river water samples on a large scale.