Antibacterial properties of cetyltrimethylammonium bromide-stabilized green silver nanoparticles against methicillin-resistant Staphylococcus aureus.

Silver nanoparticles (AgNPs) were synthesized using Artemisia capillaris extracts in the absence and presence of stabilizers, and the antibacterial activities of the AgNPs against methicillin-resistant Staphylococcus aureus (MRSA) were determined by a minimum inhibitory concentration (MIC) assay. Two stabilizers, cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), were utilized during the one-step synthesis to increase the colloidal stability of the AgNPs. The extract of A. capillaris was used as a reducing agent to convert silver ions into AgNPs. Sharp surface plasmon resonance bands in the range of 423-426 nm were observed in the UV-Visible spectra of the AgNPs, which indicated that the AgNPs were predominantly spherical shaped. Their average diameter, which ranged from 15.11 to 16.54 nm, was measured from high-resolution transmission electron microscopy images. Remarkably, the CTAB-stabilized AgNPs exhibited greater antibacterial activity (2- to 8-fold increase, MIC 15.6-62.5 μg/mL) against MRSA compared with the extract, AgNPs prepared in the absence of stabilizers, and SDS-stabilized AgNPs. The results indicate that CTAB-stabilized AgNPs prepared using plant extracts as reducing agents are very promising for the development of novel antibacterial agents.