As one of the most popular carbon-based nanomaterials, graphene oxide (GO) has the potential to be released in aquatic environment and interact with some coexistent organic pollutants, such as perfluorooctanesulfonate (PFOS), which is an emerging persistent organic pollutant. In this study, the adsorption of PFOS on GO in the presence of fulvic acid (FA), the impacts of GO and FA on PFOS toxicokinetics in carp (Cyprinus carpio), and in vitro digestion behaviors were examined. The results indicated that PFOS could be strongly adsorbed on GO with a Freundlich affinity coefficient K