Antibacterial Action and Physicochemical Properties of Stabilized Silver and Gold Nanostructures on the Surface of Disperse Silica

I Mukha,А Michienkova,G Korchak,А Eremenko

doi:10.4236/jwarp.2010.22015

Abstract

This work is devoted to the synthesis and stabilization of nanosized Ag/SiO2 and Au/SiO2 disperse materials and investigation their morphology, optical and antimicrobial properties. First, Ag and Au nanoparticles (NPs) were produced in colloids via chemical (Ag) or photochemical (Au) reduction of appropriate ions. To prevent the oxidation of Ag NPs in colloid solution, external binary stabilizing agents PVP and SDS were used. Then, Ag and Au NPs (0.01-0.05% wt) were adsorbed from their colloid solutions on high disperse silica surface (Ssp=260m2/g) and samples prepared were dried. Materials obtained were studied by UV-vis, XRD, and TEM methods. Ag and Au NPs adsorbed on silica demonstrated a fair crystallinity in XRD. The surface plasmon resonance (SPR) band positions inherent to Ag and Au NPs on silica surface as well as the intensities of optical spectra were stable during 7 month and more. Obtained Ag NPs in colloids and Ag/SiO2 composites demonstrated excellent antimicrobial activity against a series of the microorganisms (Escherichia coli, Staphylococcus aurous, and Candida albicans). Au/SiO2 samples did not reveal any bactericide properties relative to the test microorganisms grown. The mechanisms of Ag(Au) NPs interaction with silica surface were analyzed.

Highlights

Water related infections belong to the one of the main health problems
The surface plasmon resonance (SPR) band positions inherent to Ag and Au NPs on silica surface as well as the intensities of optical spectra were stable during 7 month and more
That is why developed silica surface covered with OH groups offers unique environment for the fixation and stabilization of nanosized silver and gold particles (Ag and Au NPs) for applications in optics, sensing, catalysis and as bactericides

Summary

Introduction

Water related infections belong to the one of the main health problems. The most dangerous water pathogenic pollutions such as Escherichia coli, Staphylococcus aurous are resistant to biodegradation. Silver nanoparticles (NPs) or silver ions have long been known to have strong inhibitory and bactericidal effect in solutions and composites with silica films and particles (Ag/SiO2) with developed surface area [1,2]. That is why developed silica surface covered with OH groups offers unique environment for the fixation and stabilization of nanosized silver and gold particles (Ag and Au NPs) for applications in optics, sensing, catalysis and as bactericides. It is important to prevent or inhibit the aggregation of NPs and oxidation process at the nanocluster formation stage, especially in case of silver. Stabilizing agents used for NPs surface modification control the particles formation, growth and aggregation rate [4,5]

Objectives

Results

Conclusion