Department of Biology, Jackson State University, Jackson, MS 39217, USA.
Aquatic Ecology Laboratory, Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, 43212, USA.
J Nanosci Nanotechnol. 2019 Dec 1;19(12):8172-8179. doi: 10.1166/jnn.2019.16757.
We studied the size dependent toxicity of TiO₂ nanoparticles (TiO₂ NPs; 5-50 nm) of the anatase and rutile crystalline phases (including the mixture of anatase and rutile) against the model organism . All the TiO₂ NPs were characterized and their photocatalytic inactivation of was studied under the solar simulated light irradiation and dark conditions. In addition, the mechanism of toxicity was studied by measurement of reactive oxygen species (ROS), an indicator of oxidative stress. Rutile TiO₂ NPs (TiO₂-R-30 nm) of 30 nm showed the highest photocatalytic activity against (LC of 14.11 mg/L), followed by rutile TiO₂ NPs (TiO₂-R-50 nm) (LC of 35.96 mg/L). The anatase and rutile mixture of 20 nm size produced LC of 17.12 and 27.26 mg/L for A80%-R20% and A20%-R80% respectively, whereas none of the anatase TiO₂ NPs with various sizes (5 nm, 15 nm and 30 nm) showed any toxicity against . The results indicate that the rutile had higher photocatalytic activity than anatase and the toxicity is size dependent, while the mixture of anatase and rutile had the median toxicity. Hydroxyl radical formation is the major ROS causing oxidative stress in , the primary mechanism of toxicity.
我们研究了不同尺寸的锐钛矿相和金红石相（包括锐钛矿和金红石的混合物）二氧化钛纳米颗粒（TiO₂ NPs；5-50nm）对模式生物的尺寸依赖性毒性。所有 TiO₂ NPs 都经过了表征，并在模拟太阳光照射和黑暗条件下研究了它们对 的光催化灭活作用。此外，通过测量活性氧物种（ROS）来研究毒性机制，ROS 是氧化应激的一个指标。30nm 的金红石 TiO₂ NPs（TiO₂-R-30nm）对 表现出最高的光催化活性（LC 为 14.11mg/L），其次是金红石 TiO₂ NPs（TiO₂-R-50nm）（LC 为 35.96mg/L）。20nm 尺寸的锐钛矿和金红石混合物分别产生 LC 为 17.12mg/L 和 27.26mg/L，对于 A80%-R20%和 A20%-R80%，而各种尺寸（5nm、15nm 和 30nm）的锐钛矿 TiO₂ NPs 均对 没有任何毒性。结果表明，金红石比锐钛矿具有更高的光催化活性，且毒性具有尺寸依赖性，而锐钛矿和金红石的混合物具有中等毒性。羟基自由基的形成是导致 氧化应激的主要 ROS，是毒性的主要机制。
