Exploring the antioxidant activity and cytotoxicity of the reduced graphene oxide-based nanocomposite.

In the current study, the radical scavenging activity and cytotoxicity of reduced graphene oxide (rGO), mediated by titanium dioxide (TiO) nanocomposite, have been explored. The sol-gel method was utilized to synthesize TiO nanoparticles without surfactants, and the improved Hummer's method for the graphene oxide (GO) was followed by the thermal reduction method to obtain rGO. The single-step hydrothermal process was utilized for the synthesis of GO@TiO and rGO@TiO nanocomposites. Fourier transform infrared spectrum, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), and Raman spectrum of the nanocomposites were investigated. XRD and Raman spectra confirm the anatase phase TiO formation on the 2D layer of the rGO nanosheet. FESEM and HR-TEM confirmed the spherical TiO with a 6.75 ± 1.42 nm diameter decorated on a 2D rGO nanosheet. The rGO@TiO (91.18%) exhibited higher antioxidant properties than the GO@TiO (70.00%) nanocomposite at 400 µg/mL concentration, evaluated by the DPPH method. Moreover, the nanocomposite exhibits stronger scavenger activity towards the hole scavenger than the electron scavenger. The rGO@TiO nanocomposite showed less cytotoxicity towards L929 cells compared to TiO nanoparticles, GO, rGO, and GO@TiO. The antibacterial properties of the rGO against Staphylococcus aureus bacteria were enhanced by adding TiO nanoparticles. Thus, the results support the potential antioxidant properties of rGO-based nanocomposites that can be explored for biomedical and environmental applications.