Investigate the biological activities of Lawsonia inermis extract synthesized from TiO2 doped graphene oxide nanoparticles.

ABSTRACT

Nanoparticles of titanium dioxide (TiO2) were made by reacting graphene oxide (GO) with Lawsonia inermis leaf extract. X-ray diffraction (XRD) analysis revealed crystalline TiO2 doped GO nanoparticles composed of a variety of anatase phases. Initially, UV-vis spectroscopy was performed to confirm the biogenesis of TiO2 doped GO nanoparticles (NP's). Using SEM, the research showed that the biosynthesized TiO2 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 TiO2 nanoparticles. By using fourier transform infrared (FTIR) spectroscopy, it was demonstrated that terpenoids, flavonoids, and proteins are involved in the biosynthesis and production of TiO2 doped GO nanoparticles. 2,2-diphenylpicrylhydrazyl (DPPH) assays were conducted to evaluate the free radical scavenging activity of TiO2 doped GO nanoparticles. Additionally, the TiO2 doped GO NPs had enhanced antioxidant activity when compared with the TiO2 matrix. A series of pure TiO2 and TiO2 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 TiO2 and TiO2 doped GO nanoparticles were toxic and suffered a low survival rate based on concentration. During photocatalysis, O2˙ and ˙OH radicals are rapidly produced because of the reactive species trapping experiment. It was estimated that pure TiO2 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 TiO2 doped GO NPs exhibit agglomeration and spherical shape. When tested in zebrafish embryos, TiO2 NPs are toxic at high concentrations. GO nanoparticles showed better antioxidant activity. NPs exhibited concentration dependent antioxidative activity.