High Variability in Silver Particle Characteristics, Silver Concentrations, and Production Batches of Commercially Available Products Indicates the Need for a More Rigorous Approach

Ilse De Leersnyder; Hannes Rijckaert; Leen De Gelder; Isabel Van Driessche; Pieter Vermeir

doi:10.3390/nano10071394

High Variability in Silver Particle Characteristics, Silver Concentrations, and Production Batches of Commercially Available Products Indicates the Need for a More Rigorous Approach

Nanomaterials (Basel). 2020 Jul 17;10(7):1394. doi: 10.3390/nano10071394.

Authors

Ilse De Leersnyder¹, Hannes Rijckaert², Leen De Gelder³, Isabel Van Driessche², Pieter Vermeir¹

Affiliations

¹ Department of Green Chemistry and Technology, Laboratory of Chemical Analysis (LCA), Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium.
² Department of Chemistry, Sol-gel Center for Research on Inorganic Powders and Thin film Synthesis (SCRiPTS), Faculty of Sciences, Ghent University, 9000 Ghent, Belgium.
³ Department of Biotechnology, Laboratory for Environmental Biotechnology, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium.

Abstract

Due to the beneficial properties of silver, it is anticipated that the number of commercially available applications will keep growing during the next decade. In this study, 14 different commercial products that claim to contain solid silver were characterized by visual analysis, UV-VIS spectroscopy, inductive coupled plasma optical emission spectrometry (ICP-OES), scanning transmission electron microscopy with energy dispersive x-ray spectroscopy (STEM-EDX), and dynamic light scattering (DLS). Moreover the variation between production batches-which has never been researched before-was investigated. All four techniques corroborated that some products were highly concentrated and contained spherically-shaped silver nanoparticles (AgNPs), while in others, no (solid) silver was detected or only irregularly-shaped silver particles with a high size polydispersity were present. For almost all products, a significant difference between the claimed and measured silver concentration was detected and a high variability between different production batches of the same product was observed. Our results show the need for a more rigorous approach regarding the manufacturing, labeling, and use of silver-containing products.

Keywords: (nano)particles; colloidal; consumer product; hydrosol; silver.