Measurements of release of silver ions from silver nanoparticles in biologically and environmentally relevant conditions

R.I. MacCuspie, N. Patel, K. Marchionda
Natural Immunogenics Corp,
United States

Keywords: silver nanoparticles, measurements

Summary:

Silver nanoparticles (AgNPs) exist in a cycle of transformations under environmentally and biologically relevant conditions.[1] As these conditions vary, the equilibrium of these cycles between AgNP and ionic forms are shifted, presenting measurement challenges.[2] These challenges can lead to nanoecotoxicity measurement artifacts,[3] however these artifacts canoften be avoided with proper planning . A significant portion of this talk will focus on recent advances have led to consensus methods and numerous datasets. For example, NIST Special Publication NIST SP-1200-13 describes UV-vis measurements of particle concentrations enables measurements of AgNP dissolution kinetics without processing or separation as validated by chemical analysis.[4] Additionally standardized sample preparation methods for specific applications such as textiles now exist [NIST SP-1200-8]. Example data on consumer products including commercially available dietary supplements will also be included, especially for colloidal silver products. References: 1. Akaighe, N., et al., Humic Acid-Induced Silver Nanoparticle Formation Under Environmentally Relevant Conditions. Environmental Science & Technology, 2011. 45(9): p. 3895-3901. 2. MacCuspie, R.I., et al., Challenges for physical characterization of silver nanoparticles under pristine and environmentally relevant conditions. J Environ Monit, 2011. 13(5): p. 1212-26. 3. Petersen, E.J., et al., Identification and Avoidance of Potential Artifacts and Misinterpretations in Nanomaterial Ecotoxicity Measurements. Environmental Science & Technology, 2014. 48(8): p. 4226-4246. 4. Zook, J.M., et al., Measuring agglomerate size distribution and dependence of localized surface plasmon resonance absorbance on gold nanoparticle agglomerate size using analytical ultracentrifugation. ACS Nano, 2011. 5(10): p. 8070-9.