Comparative toxicity of graphene oxide nanostructure and reduced graphene oxidesilver nanocomposite to Chlorella vulgaris through microscopic and oxidative stressanalysis

The specific physical and chemical properties of nanomaterials and enhanced application of them have raised concerns about their probable adverse impacts on the environment. Investigation of toxicity of nanomaterials on algal species can be defined as an important issue for understanding possible risks of these nanomaterials to aquatic environments. In this research, Graphene oxide nanostructure (GO) and reduced graphene oxide-silver nanocomposite (Ag-rGO) were synthesized and their characteristics were determined by XRD, SEM, EDX and Raman techniques. Chlorella vulgaris cells were subjected to GO and Ag-rGO at the same concentrations (1, 10, 20 and 30 mg/L) for a period of 24 hours for evaluating uptake and toxicity impact of these nanomaterials on the H2O2 content and contents of phenol and flavonoid. According to the results, Ag-rGO led to a significant reduction in the phenol and flavonoid contents and a significant increase in the H2O2 content in comparison with the control. GO had no considerable effect on these parameters. Images of fluorescence microscope revealed that the position of the nucleus has altered in the Ag-rGO treated cells. Nucleus had a lateral position in the control and GO treated samples while it was in the center of the Ag-rGO treated cells.

کلیدواژه ها:

Chlorella vulgaris ، Nanomaterials ، Ag-rGO nanocomposite ، Oxidative stress ، Fluorescence microscopy