Investigate the biological activities of Lawsonia inermis extract synthesized from TiO 2 doped graphene oxide nanoparticles.

Nanoparticles of titanium dioxide (TiO 2 ) were made by reacting graphene oxide (GO) with Lawsonia inermis leaf extract. X-ray diffraction (XRD) analysis revealed crystalline TiO 2 doped GO nanoparticles composed of a variety of anatase phases. Initially, UV-vis spectroscopy was performed to confirm the biogenesis of TiO 2 doped GO nanoparticles (NP's). Using SEM, the research showed that the biosynthesized TiO 2 nanoparticles were mostly spherical, polydispersed, and of a nanoscale size. Because of the energy dispersive X-ray spectroscopy (EDS) pattern, distinct and robust peaks of titanium (Ti) and oxygen (O) were observed, which were supportive of the formation of TiO 2 nanoparticles. By using fourier transform infrared (FTIR) spectroscopy, it was demonstrated that terpenoids, flavonoids, and proteins are involved in the biosynthesis and production of TiO 2 doped GO nanoparticles. 2,2-diphenylpicrylhydrazyl (DPPH) assays were conducted to evaluate the free radical scavenging activity of TiO 2 doped GO nanoparticles. Additionally, the TiO 2 doped GO NPs had enhanced antioxidant activity when compared with the TiO 2 matrix. A series of pure TiO 2 and TiO 2 doped GO nanoparticles (5, 10, 50, and 100 mg/mL) solutions were investigated for their antibacterial activities. In the current study, zebrafish embryos exposed to pure TiO 2 and TiO 2 doped GO nanoparticles were toxic and suffered a low survival rate based on concentration. During photocatalysis, O 2 ˙ and ˙OH radicals are rapidly produced because of the reactive species trapping experiment. It was estimated that pure TiO 2 nanoparticles and those doped with GO were 80% effective in degrading methyl orange(MO) after 120 min, respectively. RESEARCH HIGHLIGHTS: The UV-vis absorption spectra showed a maximum absorbance peak at 290 nm. SEM, the pure TiO 2 doped GO NPs exhibit agglomeration and spherical shape. When tested in zebrafish embryos, TiO 2 NPs are toxic at high concentrations. GO nanoparticles showed better antioxidant activity. NPs exhibited concentration dependent antioxidative activity.