Comparison of ZnO doped different phases TiO₂ nanoparticles in terms of toxicity using zebrafish (Danio rerio)

Titanium dioxide is used in many commercial and industrial areas such as paint, paper, cosmetics, textiles, and surface coating. The reasons for its use in such a wide area are its anti-corrosion and high stability. Although TiO₂ is considered to be a low-toxicity material, research has been further expanded following the recognition of the possible carcinogenic effects of TiO₂ in humans by the International Agency for Research on Cancer (IARC). The aim of this study is to compare the toxicity of TiO₂ used in many fields in different phases. In the study anatase TiO₂ synthesized by hydrothermal method and dual phase TiO₂ (anatase and rutile phase) structures obtained by thermal conditioning were used and compared with commercially available TiO₂. ZnO which has similar uses like TiO₂ was also used and compared with 1% doped TiO₂ in different phases in terms of toxicity. Zebrafish (Danio rerio, D. rerio), a freshwater fish, which is widely used in toxicity assessments was preferred in this study due to its small size, fast reproduction rate, low cost, physiological and molecular similarity with humans, and genetic predisposition. Experimental investigations showed that the highest death occurred in the low concentrations of (10 ppm) ZnO doped rutile phase. 39% of the embryos died in the ZnO nanoparticle solutions prepared at low concentrations. The highest mortality at medium (100 ppm) and high (1000 ppm) concentrations were observed in the ZnO-doped rutile phase after 96 h. Similarly, the highest malformation was detected in the ZnO-doped rutile phase during the same period.