ABSTRACT
The expanding use of hybrid nanomaterials in many applications necessitates evaluation of their environmental risks. This study investigates the acute toxicity and bioaccumulation of graphene oxide - gold (GO-Au) nanohybrid in neonates (<24 hrs old) of Daphnia magna after exposure to a wide range of concentrations (1-100 mg/L). No significant mortality or immobilisation was observed after the exposure period. Microscopic observation showed an uptake of the nanohybrid and internal damage in the gut of the exposed organisms. Bioaccumulation of the GO-Au nanohybrid also occurred in a concentration-dependant manner. Continuous evaluation of the environmental risks from exposure to this nanohybrid and other advanced materials is imperative to avert disruption to the ecosystem.