title: Alpha amylase assisted synthesis of TiO₂ nanoparticles: structural characterization and application as antibacterial agents.
abstract: The enzyme alpha amylase was used as the sole reducing and capping agent for the synthesis of TiO2 nanoparticles. The biosynthesized nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopic (TEM) methods. The XRD data confirms the monophasic crystalline nature of the nanoparticles formed. TEM data shows that the morphology of nanoparticles depends upon the enzyme concentration used at the time of synthesis. The presence of alpha amylase on TiO2 nanoparticles was confirmed by FTIR. The nanoparticles were investigated for their antibacterial effect on Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentration value of the TiO2 nanoparticles was found to be 62.50 μg/ml for both the bacterial strains. The inhibition was further confirmed using disc diffusion assay. It is evident from the zone of inhibition that TiO2 nanoparticles possess potent bactericidal activity. Further, growth curve study shows effect of inhibitory concentration of TiO2 nanoparticles against S. aureus and E. coli. Confocal microscopy and TEM investigation confirm that nanoparticles were disrupting the bacterial cell wall.
authors.affiliation: Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India.
authors.forename: Razi
authors.initials: R
authors.lastname: Ahmad
authors.affiliation: Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India.
authors.forename: Mohd
authors.initials: M
authors.lastname: Mohsin
authors.affiliation: Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India.
authors.forename: Tokeer
authors.initials: T
authors.lastname: Ahmad
authors.affiliation: Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India. Electronic address: msardar@jmi.ac.in.
authors.forename: Meryam
authors.initials: M
authors.lastname: Sardar
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology; D000516:alpha-Amylases / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; C009495:titanium dioxide; D014025:Titanium; D000516:alpha-Amylases
keywords: Antibacterial effect; Minimum inhibitory concentration; TEM; TiO(2) nanoparticles