title: Facile method for the synthesis of silver nanoparticles using 3-hydrazino-isatin derivatives in aqueous methanol and their antibacterial activity.
abstract: BACKGROUND
  A new method for preparation of silver nanoparticles (AgNPs) based on using hydrazino-isatin derivatives in an aqueous methanol reaction medium is reported here. AgNPs were prepared using silver nitrate solubilized in a water core as the source of silver ions and 3-hydrazino-isatin derivatives (3-hydrazino-isatin [IsH] and 1-benzyl-3-hydrazino-isatin [BIsH]) solubilized in methanol core as a reducing agent. The proposed method is effective, rapid, and convenient. X-ray diffraction (XRD), energy dispersive X-ray analysis, scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used for characterization of the AgNPs. The TEM micrographs confirmed that the nanopowders consist of well-dispersed agglomerates of grains with a narrow size distribution of 18-21 nm and 17-20 nm. The AgNPs, as well as BIsH, showed high antimicrobial and bactericidal activity against the Gram-positive Bacillus subtilis and Gram-negative Micrococcus luteus and Proteus vulgaris, as well as antifungal activities against Saccharomyces cerevisiae. On the other hand, they were not effective against the Gram-negative Escherichia coli.
  
  
  OBJECTIVE
  A simple, effective, rapid, and convenient chemical reduction method for the synthesis of AgNPs in an aqueous methanol reaction medium using hydrazino-isatin derivatives and studying their antibacterial effect.
  
  
  RESULTS
  IsH and BIsH are remarkably powerful reductants for Ag+ ions in an aqueous methanol medium, which could be considered as a simple chemical reduction method for formation of AgNPs. The AgNP formation depends on the solubility of the hydrazino-isatin derivatives. BIsH gave more AgNPs than IsH, as observed from XRD. The formation of AgNPs is attributed to the adsorption of hydrazine derivatives and/or interparticle interaction on the surface of AgNP through electrostatic interactions between the lone pair electrons of the hydrazino group (C=N-NH2) and the positive surface of AgNPs. AgNPs and BIsH showed high antimicrobial and bacterial activity.
  
  
  CONCLUSIONS
  In summary, it is shown that IsH and BIsH are remarkably powerful reductants for Ag+ ions in an aqueous methanol medium. BIsH gave more AgNPs than IsH, as observed from XRD due to better solubility of the BIsH than IsH in aqueous-methanol. The formation of AgNPs is attributed to the adsorption of hydrazine derivatives and/or interparticle interaction on the surface of AgNPs through electrostatic interactions between the lone pair electrons of the hydrazino group (C=N-NH2) and the positive surface of AgNPs. The AgNps as well as BIsH ligand showed high antimicrobial and bactericidal activity.
authors.affiliation: Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia ; Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, Alexandria, Egypt.
authors.forename: Ayman
authors.initials: A
authors.lastname: El-Faham
authors.affiliation: Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia ; Polymer Materials Research Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technology Applications, New Borg El-Arab City, Alexandria, Egypt.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Elzatahry
authors.affiliation: Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Zeid A
authors.initials: ZA
authors.lastname: Al-Othman
authors.affiliation: Bioproducts Research Chair, Zoology Department, Faculty of Science, King Saud University, Saudi Arabia ; Natural and Microbial Products Department, National Research Centre, Dokki, Cairo, Egypt.
authors.forename: Elsayed Ahmed
authors.initials: EA
authors.lastname: Elsayed
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D007510:Isatin / Q000031:analogs & derivatives; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D000432:Methanol; D008826:Microbial Sensitivity Tests; D016982:Micrococcus luteus / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D050997:Nanomedicine; D036103:Nanotechnology; D011514:Proteus vulgaris / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology*; D014867:Water
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D014867:Water; D012834:Silver; D007510:Isatin; D000432:Methanol
keywords: 1-benzyl-3-hydrazinoisatin; SEM; TEM; antimicrobial; silver nanoparticles