Ultrasmall,Ligand-Free Ag Nanoparticles with High Antibacterial Activity Prepared by Pulsed Laser Ablation in Liquid

Since ancient times,silver and its compounds have been known to have a broad spectrum of antimicrobial activities for bacteria,fungi,and viruses. due to the increasing bacterial resistance to classic antibiotics,the investigations of ag nps have increased. herein,we present the preparation of ligand-free ag nps with 3 and 20 nm sizes by applying picosecond laser ablation in liquid at 355 and 1065 nm. our laser processing system allows a high control on particle sizes. the produced nanoparticles were characterized by means of transmission electron microscopy,uv-vis spectroscopy,and x-ray diffraction. the size effect on the antibacterial activity of ag nps was tested against e. coli and s. aureus. the growth curves of bacteria were monitored at 0-5 mg/l of ag nps by a multimode microplate reader. the size effects as well as the concentration of ag nps on their antibacterial activity are discussed. � 2016 l�szl� kor�si et al.