Toxicity effect of graphene oxide on growth and photosynthetic pigment of the marine alga Picochlorum sp. during different growth stages.

Graphene oxide (GO), a recently discovered material, has been investigated for many applications in various fields. Thus, an immense awareness should be paid on the potential effects of the material on the environment as huge quantities of GO may get to the environment. Aquatic organisms, marine algae as an example, are exposed to such material when disposed to the environment. Accordingly, it is significant to assess the probable interactions of GO with algae in evaluating its possible environmental risks. In this study, we have examined the effect of different concentrations of GO on Picochlorum sp. during the different growth phases. The results showed that the toxicity of GO increases with increasing its concentration. The lowest concentration (0.5 mg L-1) was found to improve the algae growth and pigment content of Picochlorum sp. In contrast, higher GO concentrations had a negative consequence on the growth of algae and photosynthetic pigment concentration.