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.