Investigations on the in-vivo toxicity analysis of reduced graphene oxide/TiO ₂ nanocomposite in zebrafish embryo and larvae (Danio rerio)

The growing production and widespread use of nanomaterials are a severe concern to human health. Typically, titanium dioxide (TiO ₂ ) incorporated reduced graphene oxide (RGO), and graphene oxide (GO) has grown considerably due to their wide range of applications in nanomedicine. They are used in wound healing, drug delivery, tissue engineering and biosensor. In this work, RGO/TiO ₂ nanocomposite was synthesized by varying the TiO ₂ concentration, and the toxicity assessment was done using the zebrafish embryo model. Further, the obtained RGO/TiO ₂ nanocomposites were characterized through SEM, TEM, XRD, XPS, FTIR, UV and Raman analysis. The RGO/TiO ₂ nanocomposite is found to be biocompatible. Zebrafish body length, heartbeat count and survival percentage were carefully measured in sets of controlled experiments. Especially, the RGO/TiO ₂ nanocomposite showed very low toxicity to the zebra fish embryos at lower concentration of 30 μg ml. Also, the toxicity of the nanocomposites increases with increase in the concentration up to 1.0 mg mL ⁻¹ . RGO/TiO ₂ nanocomposite at higher concentration generates reactive oxygen species (ROS) and causes teratogenicity and cardiotoxicity. The results showed that the toxicity effect of RGO/TiO ₂ is concentration dependent. The outcomes of present work contribute to the use of the RGO/TiO ₂ composites in nanomedicine.