Evaluating the toxic effects of graphene oxide and gold nanorods on aquatic organisms

Abstract

The development of novel nanomaterials has been the focus of a number of research groups in recent years. Nanoscale materials are characterized by presenting size ranging between 1 and 100 nm in at least one of its dimensions. Due to the small size, these nanomaterials have specific properties that allow their application in several scientific and technological areas. Aquatic environments may be the target of nanomaterials as a result of the manufacturing process or due to their use in consumer products. In these environments, the interactions of the nanoscale materials with living organisms have not been well characterized, and therefore there is the possibility of risk to the biota. The aim of this study is to evaluate the possible toxic effects caused by the presence of graphene oxide nanoparticles and gold nanorods on the cladoceran Ceriodaphnia silvestrii and the fish Danio rerio. The studies will be carried out via acute and chronic exposures, in which we will determine the median effective and lethal concentrations for organisms, and effects on reproductive system of C. silvestrii. Histological aspects and cell viability of D. rerio will also be investigated. Embryos and sac-fry stages of D. rerio also will be exposed to nanoparticles for assessments of hatching rate and eggs survival, effects on breathing movements, heartbeat, size and individual weight. The toxicity of nanoparticles has been discussed in the literature from in vitro evaluations; however, in vivo studies may be more representative for understanding the changes that may be caused by the presence of nanomaterials in these environmens. (AU)