Comparative study of antimicrobial activity of AgBr and Ag nanoparticles (NPs).

Petr Suchomel,Jan Hrbac,Robert Prucek,Radek Zboril,Renata Vecerova,Libor Kvitek,Ales Panacek

doi:10.1371/journal.pone.0119202

Petr Suchomel, Jan Hrbac + Show 5 more

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https://doi.org/10.1371/journal.pone.0119202

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Abstract

The diverse mechanism of antimicrobial activity of Ag and AgBr nanoparticles against gram-positive and gram-negative bacteria and also against several strains of candida was explored in this study. The AgBr nanoparticles (NPs) were prepared by simple precipitation of silver nitrate by potassium bromide in the presence of stabilizing polymers. The used polymers (PEG, PVP, PVA, and HEC) influence significantly the size of the prepared AgBr NPs dependently on the mode of interaction of polymer with Ag+ ions. Small NPs (diameter of about 60–70 nm) were formed in the presence of the polymer with low interaction as are PEG and HEC, the polymers which interact with Ag+ strongly produce nearly two times bigger NPs (120–130 nm). The prepared AgBr NPs were transformed to Ag NPs by the reduction using NaBH4. The sizes of the produced Ag NPs followed the same trends – the smallest NPs were produced in the presence of PEG and HEC polymers. Prepared AgBr and Ag NPs dispersions were tested for their biological activity. The obtained results of antimicrobial activity of AgBr and Ag NPs are discussed in terms of possible mechanism of the action of these NPs against tested microbial strains. The AgBr NPs are more effective against gram-negative bacteria and tested yeast strains while Ag NPs show the best antibacterial action against gram-positive bacteria strains.

Highlights

Silver nanoparticles (Ag NPs) and nanoparticles of insoluble silver compounds such as Ag2O, AgOH or AgX (X = Cl, Br or I) became one of the most discussed branches of nanoscience in the several last decades [1]
The realized antibacterial assays showed differences between antimicrobial action of AgBr and Ag nanoparticles and Ag+ ions used as reference material
The differences were connected to the interaction of the silver based materials with the cell walls of microorganisms

Summary

Introduction

Silver nanoparticles (Ag NPs) and nanoparticles of insoluble silver compounds such as Ag2O, AgOH or AgX (X = Cl, Br or I) became one of the most discussed branches of nanoscience in the several last decades [1]. Ag NPs attract great attention in the scientific research because of their unique physical, chemical, optical and biological properties which predetermine them for use in various chemical, medical and industrial applications [2]. Diverse biological properties, namely antifungal, antiviral and antibacterial activities together with cytotoxicity of silver NPs are intensely studied because of expected inability of bacteria to develop resistance against their antibacterial action. Antimicrobial Activity of AgBr and Ag NPs study design, data collection and analysis, decision to publish, or preparation of the manuscript

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