Developing and interpreting aqueous functional assays for comparative property-activity relationships of different nanoparticles

Justin M Kidd; David Hanigan; Lisa Truong; Kiril Hristovski; Robert Tanguay; Paul Westerhoff

doi:10.1016/j.scitotenv.2018.02.107

Developing and interpreting aqueous functional assays for comparative property-activity relationships of different nanoparticles

Sci Total Environ. 2018 Jul 1:628-629:1609-1616. doi: 10.1016/j.scitotenv.2018.02.107. Epub 2018 Feb 28.

Authors

Justin M Kidd¹, David Hanigan², Lisa Truong³, Kiril Hristovski⁴, Robert Tanguay³, Paul Westerhoff⁵

Affiliations

¹ Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, School of Sustainable Engineering and the Built Environment, Tempe, AZ 85287-3005, United States.
² Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States.
³ Department of Environmental and Molecular Toxicology, Environmental Health Sciences Center, Marine and Freshwater Biomedical Sciences Center, Oregon State University, Corvallis, OR 97331-7301, United States.
⁴ The Polytechnic School, Fulton Schools of Engineering, Arizona State University, Mesa, AZ 85212, United States.
⁵ Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, School of Sustainable Engineering and the Built Environment, Tempe, AZ 85287-3005, United States. Electronic address: p.westerhoff@asu.edu.

PMID: 30045577
DOI: 10.1016/j.scitotenv.2018.02.107

Abstract

It is difficult to relate intrinsic nanomaterial properties to their functional behavior in the environment. Unlike frameworks for dissolved organic chemicals, there are few frameworks comparing multiple and inter-related properties of engineered nanomaterials (ENMs) to their fate, exposure, and hazard in environmental systems. We developed and evaluated reproducibility and inter-correlation of 12 physical, chemical, and biological functional assays in water for eight different engineered nanomaterials (ENMs) and interpreted results using activity-profiling radar plots. The functional assays were highly reproducible when run in triplicate (average coefficient of variation [CV]=6.6%). Radar plots showed that each nanomaterial exhibited unique activity profiles. Reactivity assays showed dissolution or aggregation potential for some ENMs. Surprisingly, multi-walled carbon nanotubes (MWCNTs) exhibited movement in a magnetic field. We found high inter-correlations between cloud point extraction (CPE) and distribution to sewage sludge (R²=0.99), dissolution at pH8 and pH4.9 (R²=0.98), and dissolution at pH8 and zebrafish mortality at 24hpf (R²=0.94). Additionally, most ENMs tend to distribute out of water and into other phases (i.e., soil surfaces, surfactant micelles, and sewage sludge). The activity-profiling radar plots provide a framework and estimations of likely ENM disposition in the environment.

Keywords: Exposure; Fate; Hazard; Nanoparticle; Water.