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.