Preparation and antibacterial activity of Fe₃O₄@Ag nanoparticles

Abstract

Bifunctional Fe3O4@Ag nanoparticles with both superparamagnetic and antibacterial properties were prepared by reducing silver nitrate on the surface of Fe3O4 nanoparticles using the water-in-oil microemulsion method. Formation of well-dispersed nanoparticles with sizes of 60 ± 20 nm was confirmed by transmission electron microscopy and dynamic light scattering. X-ray diffraction patterns and UV–visible spectroscopy indicated that both Fe3O4 and silver are present in the same particle. The superparamagnetism of Fe3O4@Ag nanoparticles was confirmed with a vibrating sample magnetometer. Their antibacterial activity was evaluated by means of minimum inhibitory concentration value, flow cytometry, and antibacterial rate assays. The results showed that Fe3O4@Ag nanoparticles presented good antibacterial performance against Escherichia coli (gram-negative bacteria), Staphylococcus epidermidis (gram-positive bacteria) and Bacillus subtilis (spore bacteria). Furthermore, Fe3O4@Ag nanoparticles can be easily removed from water by using a magnetic field to avoid contamination of surroundings. Reclaimed Fe3O4@Ag nanoparticles can still have antibacterial capability and can be reused.

Synthesis and antibacterial properties of Fe3O4-Ag nanostructures

“…In the range from 750 to 1350 cm -1 there is the wide band, which may be attributed to stretching vibrations of O-H and C-O-H 29 . The band is more intensive against a background of the nanostructure, what may be caused by additional C-N stretching vibrations 19 . The C-N stretching vibrations are characteristic for aliphatic amines and occur in the range of 1020-1250 cm -1 .…”

“…The mechanism of the polyol reaction is still under study. Polyethylene glycol decomposing to acetaldehyde 19 can be a reducer to reduce FeCl 3 to Fe 3 O 4 . Temperature is a factor which infl uence on glycol reduction potential.…”

Assessing the efficacy of zinc oxide nanoparticles against Penicillium expansum by automated turbidimetric analysis

“…Silver has been in use since time immemorial in the form of metallic silver, silver nitrate, silver sulfadiazine for the treatment of burns, wounds and several bacterial infections (Rai et al 2009). However, silver nanoparticles have some risks as the exposure to silver can cause agyrosis (Rai et al 2009) and it is toxic to mammalian cells (Gong et al 2007) unless if used in minute concentrations. Copper and its compounds have also been used for centuries as effective antibacterial, antifungal and antiviral agents (Ingle et al 2014).…”

Antimicrobial Activities of Silver Nanoparticles Synthesized by Using Water Extract of Arnicae anthodium

“…The use of metallic nanoparticles is promising because they show excellent antibacterial properties due to their large surface area to volume ratio. This is very interesting for researchers due to the growing microbial resistance to metal ions, antibiotics and the development of resistant strains [2]. The chemical and physical synthesis of nanoparticles is expensive and often involves the use of toxic hazardous chemicals which may pose environmental risks [3].…”