title: {101}-{001} Surface Heterojunction-Enhanced Antibacterial Activity of Titanium Dioxide Nanocrystals Under Sunlight Irradiation.
abstract: The {101}-{001} surface heterojunction constructed on polyhedral titanium dioxide (TiO2) nanocrystals has recently been proposed to be favorable for the efficient electron-hole spatial separation due to the preferential accumulation of electron and hole on {101} and {001} facets, respectively. The formed free electron and hole can promote reactive oxygen species (ROS) production, which potentially can be used for inactivation of bacteria. In the present study, a series of truncated octahedral bipyramid TiO2nanocrystals (T1, T2, T3, and T4) coexposed with {101} and {001} facets were prepared to form various ratios of {101} to {001} facet for optimization of electron-hole spatial separation efficiency. All these polyhedral TiO2nanocrystals could more significantly produce ROS than spherical TiO2nanocrystals (Ts), exhibiting the higher antibacterial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria under simulated sunlight irradiation. Among these polyhedral TiO2nanocrystals, T3 with a {101}/{001} ratio of 1.78 was found to be the best one showing the highest ROS and the most potent antibacterial performance. Scanning electron microscope images of bacteria displayed that the surface membrane structure of both E. coli and S. aureus bacteria was influenced to different extents by these TiO2nanocrystals, where T3 caused the most severe membrane damage. The molecular mechanism underlying the high antibacterial activity of TiO2nanocrystals was ascribed to activation of oxidative stress as evidenced by intracellular ROS production, glutathione depletion, and membrane lipid peroxidation in bacteria. The surface heterojunction as a completely new strategy holds great promise to develop effective antibacterial nanomaterials.
authors.affiliation: Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun, Jilin 130022, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun, Jilin 130022, China.|University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun, Jilin 130022, China.|University of Science and Technology of China , 96 Jinzhai Road, Hefei, Anhui 230026, China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun, Jilin 130022, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun, Jilin 130022, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Sun
authors.affiliation: Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun, Jilin 130022, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Jian
authors.affiliation: School of Chemistry and Life Science, Changchun University of Technology , 2055 Yan'an Street, Changchun, Jilin 130012, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Feng
authors.affiliation: School of Chemistry and Life Science, Changchun University of Technology , 2055 Yan'an Street, Changchun, Jilin 130012, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Li
authors.affiliation: Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun, Jilin 130022, China.|University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, China.|University of Science and Technology of China , 96 Jinzhai Road, Hefei, Anhui 230026, China.
authors.forename: Haiyuan
authors.identifier: http://orcid.org/0000-0003-4076-1771
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000900:Anti-Bacterial Agents; D004926:Escherichia coli; D053758:Nanoparticles; D013211:Staphylococcus aureus; D013472:Sunlight; D014025:Titanium
chemical_list: D000900:Anti-Bacterial Agents; C009495:titanium dioxide; D014025:Titanium
keywords: ROS production; antibacterial activity; nanocrystals; surface heterojunction; titanium dioxide