The application of nanocomposite materials fabricated from titanium dioxide nanoparticles (TiO₂ NPs) and different carbon (C) allotropes have gained popularity in water treatment applications due to their synergistic properties. Studies to date have focused on simple forms of nanomaterials (NMs), however, with the technology development, there is a dramatic increase in production and application of these complex NMs which could result in toxicological impacts on organisms when released into aquatic environments. This raises serious concerns about their safety and the need to ascertain their potential adverse effects on aquatic organisms. While conjugated TiO₂ NPs/carbon-based nanohybrids (TiO₂/C-NHs) may exhibit enhanced photocatalytic activity, there is no research in the scientific community regarding their toxicological effects on D. magna, which are indicators of freshwater pollution. In this study, two under-represented TiO₂/C-NHs (i.e., TiO₂- conjugated carbon nanofiber (CNF), and TiO₂-conjugated multi-walled carbon nanotube (CNT)) were investigated for their toxic effects on D. magna, through a series of acute toxicity tests with a set of sublethal biochemical biomarkers of oxidative stress. The lethal toxicity and oxidative stress formation of TiO₂/C-NHs over 48 h revealed a concentration-dependant increase in D. magna mortality. The primary mechanism identified was the generation of ROS, which was in line with toxicity results. Light microscopy and CytoViva® images visualized D. magna interaction with the NPs, which accumulated and appeared as dark materials in the lines of the gut tract. The collective results indicate that TiO₂/C-NHs have the potential to cause an effect on freshwater organisms when released into the environment. However, the relevance of TiO₂/C-NHs effects needs further chronic toxicity studies since they show promise to be used in nano-bioremediation materials to treat wastewaters.

由二氧化钛纳米粒子 (TiO ₂ NPs) 和不同的碳 (C) 同素异形体制成的纳米复合材料的应用由于它们的协同特性而在水处理应用中得到普及。迄今为止的研究主要集中在简单形式的纳米材料 (NM)，然而，随着技术的发展，这些复杂的 NM 的生产和应用急剧增加，当释放到水生环境中时可能对生物体产生毒理学影响。这引起了对其安全性的严重关注，并需要确定它们对水生生物的潜在不利影响。而共轭 TiO ₂ NPs/碳基纳米杂化物 (TiO ₂/C-NHs) 可能表现出增强的光催化活性，科学界尚无关于其对淡水污染指标D. magna的毒理学影响的研究。在这项研究中，研究了两种代表性不足的 TiO ₂ /C-NHs（即TiO ₂ - 共轭碳纳米纤维 (CNF) 和 TiO ₂ -共轭多壁碳纳米管 (CNT)）对D. magna，通过一系列急性毒性试验，使用一组氧化应激的亚致死生化生物标志物。_{TiO 2} /C-NHs 在 48 小时内的致死毒性和氧化应激形成显示出浓度依赖性增加D. magna死亡率。确定的主要机制是 ROS 的产生，这与毒性结果一致。光学显微镜和 CytoViva® 图像显示D. magna与 NPs 的相互作用，NPs 在肠道线中积累并显示为深色物质。综合结果表明，TiO ₂ /C-NHs 在释放到环境中时有可能对淡水生物造成影响。然而，TiO ₂ /C-NHs 效应的相关性需要进一步的慢性毒性研究，因为它们有望用于纳米生物修复材料来处理废水。