Toxicity assessment of TiO2-MWCNT nanohybrid material with enhanced photocatalytic activity on Danio rerio (Zebrafish) embryos

• Published in: Ecotoxicology and environmental safety 2018-12, Vol.165, p.136-143
• Main Authors: Da Silva, Gabriela H., Clemente, Zaira, Khan, Latif U., Coa, Francine, Neto, Lais L.R., Carvalho, Hudson W.P., Castro, Vera L., Martinez, Diego Stéfani T., Monteiro, Regina T.R.
• Format: Article
• Language: English
• Subjects: Carbon nanotubes; Nanocomposites; Nanohybrids; Nanotoxicity; TiO2
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2018.08.093

The increasing production and use of nanomaterials is causing serious concerns about their safety to human and environmental health. However, the applications of titanium dioxide nanoparticles (TiO2NP) and multiwalled carbon nanotubes (MWCNT) hybrids has grown considerably, due to their enhanced photocatalytic efficiency. To our knowledge, there are no reports available to the scientific community about their toxicity. In this work, we perform a toxicity assessment of TiO2NP and TiO2-MWCNT nanohybrid materials using Zebrafish embryos standardized 96 h early life stage assay, under different exposure conditions (with and without UV light exposure). After exposure the parameters assessed were acute toxicity, hatching rate, growth, yolk sac size, and sarcomere length. In addition, μ-probe X-ray fluorescence spectroscopy (µ-XRF) was employed to observe if nanoparticles were uptaken by zebrafish embryos and consequently accumulated in their organisms. Neither TiO2NP nor TiO2-MWCNT nanohybrids presented acute toxicity to the zebrafish embryos. Moreover, TiO2NP presents sublethal effects for total length (with and without UV light exposure) on the embryos. This work contributes to the understanding of the potential adverse effects of the emerging nanohybrid materials towards safe innovation approaches in nanotechnology. [Display omitted] •TiO2-MWCNT was synthesized by cheap mechanical mixing method.•TiO2-MWCNT was more photocatalytic than TiO2 nanoparticle, extending the activity to visible light region.•The nanohybrid did not present toxicity to Danio rerio embryos with and without UV illumination.•TiO2 and TiO2-MWCNT was ingested by D. rerio larvae.