In today's technology world, we are witnessing the emergence of a form of nanotechnology science that has affected many aspects of life. The use of nanoparticles (NPs) is very wide, from wastewater treatment to use in cosmetic products and cancer treatment and diagnosis.But in addition to the well-known advantages, their disadvantages should also be identified. Due to the pollution caused by chemical synthesis, which is more common in the production of nanoparticles and its high cost, we are looking for an alternative. Today, special attention can be paid to biological synthesis, as chemical pollution caused by raw materials is not seen in the product, and its cost is more affordable, the size and shape of nanoparticles can be controlled. In this research, for the green synthesis of titanium dioxide nanoparticles (TiO2), Cystoceria brown algae cell extract was used, and the physico-chemical characteristics of the synthesized nanoparticles were measured by methods such as Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Fourier-Transform Infrared (FT-IR) spectroscopy, and UV-visible. In conclusion, our results revealed that Cystosria can be used as a good organism for biological synthesis of TiO2 NPs.
