title: Antibacterial effect of various shapes of silver nanoparticles monitored by SERS.
abstract: A comparative evaluation of antimicrobial effect of synthesized silver nanoparticles (AgNPs) of different shapes using different methods was performed. Spherical, triangular and hexagonal AgNPs with an average size of 40 nm were chemically prepared and characterized by transmission electron microscope (TEM) and UV-visible spectroscopy. The antimicrobial effect of these different AgNPs against the gram negative bacterium Escherichia coli (E. coli) was studied by surface enhanced Raman spectroscopy (SERS), the evaluation of growth curves and inhibition zones. SERS proved to be sensitive to monitor the changes that occurred in the bacterial cells upon interaction with AgNPs, which qualitatively compared well with the data provided by the reference methods. However, as SERS is already sensitive to initial changes in the chemistry of bacteria due to the antibacterial effect of the AgNPs, fast and detailed information is provided by SERS as opposed to the classical reference methods based on the evaluation of growth curves and inhibition zones. The results of this work also demonstrate that hexagonal AgNPs display the highest antibacterial effect when compared to other NPs shapes, with triangular AgNPs exhibiting no antibacterial effect under the adopted conditions.
authors: Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/151, A-1060 Vienna, Austria; Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt. Electronic address: mar_zah2002@yahoo.com.
authors: Marwa R
authors: MR
authors: El-Zahry
authors: Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Austria; Department of Plant Pathology, Faculty of Agriculture, Assiut University, 71526 Assiut, Egypt.
authors: Amer
authors: A
authors: Mahmoud
authors: Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt.
authors: Ibrahim H
authors: IH
authors: Refaat
authors: Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt.
authors: Horria A
authors: HA
authors: Mohamed
authors: Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Austria.
authors: Holger
authors: H
authors: Bohlmann
authors: Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/151, A-1060 Vienna, Austria.
authors: Bernhard
authors: B
authors: Lendl
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning / Q000379:methods; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D012834:Silver
keywords: Antibacterial effect; Different shapes; SERS; Silver nanoparticles; TEM