Green synthesis of titanium dioxide nanoparticles using Azadirachta indica leaf extract and evaluation of their antibacterial activity

The present study deals with the synthesis of titanium dioxide nanoparticles using Azadirachta indica leaf extract. FTIR study reveals the presence of terpenoids, flavonoids and proteins considered responsible for the formation and stabilization of titanium dioxide nanoparticles while the XRD studies revealed the crystalline nature of titanium dioxide nanoparticles. Transmission electron microscopy images showed the spherical shape and size ranged from 15 to 50 nm. SEM study revealed that TiO2 nanoparticles were spherical in shape and their size ranged from 25 to 87 nm. The antibacterial activity of synthesized TiO2 nanoparticles and TiO2 compound was assayed against Escherichia coli, Bacillus subtilis, Salmonella typhi and Klebsiella pneumoniae. The results of the present study showed that TiO2 nanoparticles inhibited the growth of all the tested microorganisms. The antibacterial effect is more pronounced in case of TiO2 nanoparticles as compared with TiO2 compound. The lowest MIC (minimum inhibitory concentration) value i.e. 10.42 μg/mL of nanoparticles was observed against Salmonella typhi and Escherichia coli whereas lowest MBC value i.e. 83.3 μg/mL was observed against Klebsiella pneumoniae.