Computational-experimental approach in Environmental Nanotoxicology: Tannic Acid, Graphene-oxide and Atrazine molecular interactions and mixture toxicity
There is a growing concern of the scientific community and regulatory agencies on the potential impacts of nanomaterials on human and environmental health, especially due to the expansion of nanotechnology in industry. Several factors, such as modification of nanomaterials in the environment via dissolution processes, aggregation, formation of biomolecular coronas and interactions with other chemical compounds (e.g., organic and inorganic pollutants) are determinants on the toxicity of nanomaterials. In this context, the main objective of this thesis was to develop an innovative approach integrating theoretical and experimental methodologies to understand the interactions between graphene oxide (GO) and organic pollutants commonly encountered in the environment; and the impacts of such interactions on the ecotoxicity of the nanomaterial considering co-exposure scenarios (joint toxicity). Thus, using computational approaches, such as Density Functional Theory, Molecular Dynamics, and Coarse-grained, we studied the interactions between GO, natural organic matter (i.e., tannic acid) and organic pollutants (i.e., atrazine) on the atomic and molecular scale. Together with the knowledge obtained by the computational simulations, we performed the biological experiments with the model organisms C. elegans and Danio rerio. By considering the feedback between both approaches, we advanced to understand the mechanisms involved in the nanoecotoxicity of GO in the environment regarding co-exposure scenarios with classical pollutants. The results of this thesis will support the risk assessment studies on nanomaterials, as well as the future applications of GO in environmental nanotechnology.