Silver nanoparticles in complex media: an easy procedure to discriminate between metallic silver nanoparticles, reprecipitated silver chloride, and dissolved silver species.

Kateryna Loza,Matthias Epple

doi:10.1039/c8ra04500c

Abstract

Silver nanoparticles undergo oxidative dissolution in water upon storage. This occurs in pure water as well as in more complex media, including natural environments, biological tissues, and cell culture media. However, the dissolution leads to the reprecipitation of silver chloride as chloride is present in almost all relevant environments. The discrimination between dissolved silver species (ions and silver complexes) and dispersed (solid) species does not take this into account because all solid species (metallic silver and silver chloride) are isolated together. By applying a chemical separation procedure, we show that it is possible to quantify silver, silver chloride, and dissolved silver species after immersion into a typical cell culture medium (DMEM + 10% FCS). During the dissolution of metallic silver nanoparticles, about half of the dissolved silver is reprecipitated as solid silver chloride, i.e. the mere analysis of the soluble silver species does not reflect the true situation. The separation protocol is suitable for all chloride-containing media in the presence or in the absence of biomolecules.

Highlights

Silver nanoparticles are widely used due to their antibacterial action in consumer products and in medicine.[1,2,3,4,5,6,7,8,9,10] This has resulted in growing concerns about possible risks for humans and the environment.[3,11,12,13,14,15,16,17,18] in the majority of cases silver nanoparticles show an indirect action, acting as a depot for silver ions that are responsible for biocidal action.[19]
By applying a chemical separation procedure, we show that it is possible to quantify silver, silver chloride, and dissolved silver species after immersion into a typical cell culture medium (DMEM + 10% fetal calf serum (FCS))
The silver nanoparticles were characterized by scanning electron microscopy and dynamic light scattering

Summary

Introduction

Silver nanoparticles are widely used due to their antibacterial action in consumer products and in medicine.[1,2,3,4,5,6,7,8,9,10] This has resulted in growing concerns about possible risks for humans and the environment.[3,11,12,13,14,15,16,17,18] in the majority of cases silver nanoparticles show an indirect action, acting as a depot for silver ions that are responsible for biocidal action.[19]. Silver nanoparticles in complex media: an easy procedure to discriminate between metallic silver nanoparticles, reprecipitated silver chloride, and dissolved silver species By applying a chemical separation procedure, we show that it is possible to quantify silver, silver chloride, and dissolved silver species after immersion into a typical cell culture medium (DMEM + 10% FCS).

Results

Conclusion