A sensitive and selective triple-channel optical assay based on red-emissive carbon dots for the determination of PFOS

In this study, a simple, fast and cost-effective triple-channel optical assay for the determination of PFOS has been developed. The carbon quantum dots (CDs) were prepared by one-pot hydrothermal method and employed as probe for sensing PFOS. CDs react with PFOS to form ground-state complex, which brings about the intensity changes of three signals including fluorescence, UV vis absorption and resonance light scattering (RLS). And the changes of the fluorescence and absorption signals can be used for the visual detection of PFOS. And there is a certain relationship between the three-signal changes with the concentration of PFOS, respectively. The proposed assay exhibits good selectivity and sensitivity with a limit of detection (LOD) of 18.27 nmol/L in the fluorescence signal. Fluorescence lifetime, transmission electron microscopy (TEM) images, Fourier transform infrared (FTIR) and zeta potential were investigated for the mechanism study. Furthermore, this promising approach was also successfully applied to PFOS sensing in real water samples with RSD <= 2.09%.