Preparation of silver nanoparticles via chemical reduction and their antimicrobial activity

Abstract

A simple and economic method of synthesis of silver colloid nanoparticles with controlled size is presented. By reduction of [Ag(NH3)2] + complex in sodium dodecylsulfate (SDS) micellar solution with three various reducing agents (hydrazine, formalin and ascorbic acid) the nanoparticles were produced with size below 20 nm. The average size, size distribution, morphology, and structure of particles were determined by dynamic light scattering (DLS), scanning electron microscopy (SEM), and UV/Visible absorption spectrophotometry. The influence of the reducing agent on the size of silver particles, fraction of metallic silver and their antimicrobial properties is discussed. In particular, the reduction of silver complex by hydrazine resulted in silver nanoparticles with size below 20nm. They showed high activity against Gram-positive and Gram-negative bacteria (lab isolated strains), and clinical isolated strains including highly multiresistant strains such as Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa.