Facile Synthesis of Silver Nanoparticles and Their Synergistic Antibacterial Activity in Combination with Commercial Antibiotics

We demonstrate a facile method for the synthesis of silver nanoparticles (Ag NPs) by using silver nitrate (AgNO3) as precursor, p-toluidine as reducing agent and cetyltrimethylammonium bromide (CTAB) as capping agent. The main highlight of the present synthesis is the formation of NPs at near neutral pH. The effect of the concentrations of precursor, reducing agent and capping agent, and of pH on the stability and size of the NPs has been studied using UV–vis spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM) techniques. Critical concentrations of AgNO3, reducing agent and CTAB required for the synthesis of Ag NPs are found to be 0.002 mol dm−3. The NPs prepared have been tested for antibacterial properties for a series of bacteria and they are found to have good antibacterial efficacy. In combination with some commercially available antibiotics, synergism in the antibacterial activity of the NPs has also been observed.