title: Does the antibacterial activity of silver nanoparticles depend on the shape of the nanoparticle? A study of the Gram-negative bacterium Escherichia coli.
abstract: In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag(+) (in the form of AgNO(3)). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property. To our knowledge, this is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and our results demonstrate that silver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.
authors.affiliation: Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Sukdeb
authors.initials: S
authors.lastname: Pal
authors.forename: Yu Kyung
authors.initials: YK
authors.lastname: Tak
authors.forename: Joon Myong
authors.initials: JM
authors.lastname: Song
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002462:Cell Membrane / Q000648:ultrastructure; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D050296:Microbial Viability; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D012834:Silver / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D012834:Silver