Avicennia marina mediated synthesis of TiO2 nanoparticles: its antibacterial potential against some aquatic pathogens

This study reports the synthesis of TiO2 nanoparticles through a bio-approach by Avicennia marina leaf extract to titanium source ratios of 0.03, 0.06, 0.125, 0.20, 0.25 and 0.5, and examines its antibacterial activity against some aquatic bacterial pathogens. XRD confirmed the synthesis of crystalline anatase TiO(2)NPs and showed the increase of crystallite size with increasing the ratio from 0.03 to 0.5. FT-IR approved the existence of functional groups in the extract. In visible light region, with increasing the ratio, the absorption intensity of TiO(2)NPs increased and the bandgap energy decreased. FE-SEM and TEM showed TiO2 nanoparticles-aggregated spheres with homogeneous shape and size of about 30 nm. In both the solid and liquid media, antibacterial activity of the biosynthesized TiO(2)NPs was further prominent against the Gram-positive bacteria compared with Gram-negative ones. Native mangrove A. marina leaf extract acted as a suitable reducing and stabilizing agent toward biosynthesis of TiO(2)NPs with noticeable antibacterial potential.