Toxic Effects of Copper Oxide Nanoparticles on Chlorella vulgaris

Aim: 
Exploitation of nano-based materials has increased the disposal of nanoparticles into the environment. Toxic nanomaterials pose their adverse effects and severely impact the human and environmental health. The aim of this study was to explore the toxic effects of chemically-synthesized copper oxide nanoparticles (CuO-NPs) on Chlorella vulgaris using an algal growth inhibition assay.
Materials and Methods: 
Nanoparticles were synthesized using cupric sulfate and sodium hydroxide. Synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy. C. vulgaris culture was exposed to various concentrations of CuO-NPs at intervals of 3, 6, 12, and 24 h. Growth inhibition assay of algal culture was estimated via the spectroscopic method and cell enumeration was done by Neubauer hemocytometry.
Results: 
The average diameter of CuO-NPs was ~35.85 nm. UV-Vis spectroscopy was used to confirm the configuration of CuO-NPs. Therefore, FTIR results has indicated high purity of synthesized CuO-NPs. Size of the CuO-NPs was determined by XRD. Results showed that growth of C. vulgaris microalgae was notably affected by the exposure of 2 mg/L CuO-NPs concentration exposure for 6 h.
Conclusion: 
The current work showed that CuO-NPs have significant toxic to Chlorella sp. Data analysis showed NPs have broad effects on growth of C. vulgaris and there is a correlation between nanoparticles concentration as well as their toxicity on the microalgae.