title: The synthesis of citrate-modified silver nanoparticles in an aqueous suspension of graphene oxide nanosheets and their antibacterial activity.
abstract: A composite material consisting of silver nanoparticles (Ag NPs) deposited on graphene oxide (GO) nanosheets is prepared by chemical reduction of Ag metal ions by sodium borohydride (NaBH4) in the presence of trisodium citrate acting as a stabilizing agent to prevent agglomeration of the nanoparticles. The synthesized GO/Ag NPs composite was characterized by UV/vis spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM analysis confirmed a high density of Ag NPs on the GO nanosheets with a particle size range of 2-25 nm. The activity of the GO/Ag NPs suspension as an antibacterial agent against Gram positive bacteria Staphylococcus aureus and Bacillus subtilis was investigated. The percentage of the killing bacterial colonies by Ag NPs (without GO) is found to be 96-97% while 100% of killing bacterial colonies is only obtained using GO/Ag NPs suspension. Moreover, it was also observed that leakage of sugars and proteins from the cell wall of both S. aureus and B. subtilis in interaction with GO/Ag NPs suspension is higher compared to Ag NPs (without GO) and GO nanosheets.
authors: Materials Science Division, CSIR-North East Institute of Science and Technology, Jorhat 785006, Assam, India. mnshrdas@yahoo.com
authors: Manash R
authors: MR
authors: Das
authors: Rupak K
authors: RK
authors: Sarma
authors: Sarat Ch
authors: SCh
authors: Borah
authors: Roopa
authors: R
authors: Kumari
authors: Ratul
authors: R
authors: Saikia
authors: Ashvini B
authors: AB
authors: Deshmukh
authors: Manjusha V
authors: MV
authors: Shelke
authors: Pinaki
authors: P
authors: Sengupta
authors: Sabine
authors: S
authors: Szunerits
authors: Rabah
authors: R
authors: Boukherroub
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects*; D002241:Carbohydrates / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry / Q000494:pharmacology*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011506:Proteins / Q000378:metabolism; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013211:Staphylococcus aureus / Q000187:drug effects*; D014867:Water / Q000737:chemistry* / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D002241:Carbohydrates; D011506:Proteins; D014867:Water; D019343:Citric Acid; D012834:Silver; D006108:Graphite