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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Production and Genetic Improvement Research Unit » Research » Publications at this Location » Publication #413726
Research Project: Improved Fruit, Grape and Wine Products through Precision Agriculture and Quality Component Evaluation

Location: Horticultural Crops Production and Genetic Improvement Research Unit

Title: Counterion selection for ion controls of CuO-nanoparticles is important for assessing soil biological responses

Author
item MARGENOT, ANDREW - University Of Illinois
item Rippner, Devin
item GREEN, PETER - University Of California, Davis
item SCOW, KATE - University Of California, Davis
item PARIKH, SANJAI - University Of California, Davis

Submitted to: Soil & Environmental Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/26/2024
Publication Date: 6/6/2024
Citation: Margenot, A., Rippner, D.A., Green, P.G., Scow, K.M., Parikh, S.M. 2024. Counterion selection for ion controls of CuO-nanoparticles is important for assessing soil biological responses. Soil & Environmental Health. 2(3):100094. https://doi.org/10.1016/j.seh.2024.100094.
DOI: https://doi.org/10.1016/j.seh.2024.100094

Interpretive Summary: Copper salts are often used as controls for nanoparticle (nanoscale particle) toxicology studies. An assumption to these studies is that the coordinating negatively charged ion (anion) has no effect on biological system functioning. This assumption is weak given that these chemicals are important nutrients for biological growth. We show that enzyme activities in soils, important indicators of soil microbial function, vary by coordinating anion. Some enzyme activities went up and some went down depending on the coordinating anion and land use history. Our results often showed the coordinating anion was having a larger treatment effect than the positively charged ion (cation), which confirmed the importance of proper control selection for nanoparticle toxicity studies.

Technical Abstract: Environmental evaluations of metal nanoparticles (NP) rely on metal ion controls to discriminate between effects of the metal NP and its dissolution products. However, the coordinating or counter anion used in experimental controls may potentially influence biotic ecotoxicological indicators, compromising the ability to detect nanosized effects and confounding interpretation of metal NP environmental impacts. Using the example of copper (Cu), we demonstrate that depending on the anion used in the metal ion control (CuCl2 versus CuSO4), differing and even opposite conclusions may be drawn for Cu NP effects on a key microbiological indicator (enzyme activities) in environmental samples (soils). Moreover, this effect was specific to environmental conditions (soil management system) and indicator type (enzyme class). We propose that assessments of environmental impacts of metal NP should consider multiple coordinating anion controls for a given metal, especially when the specific counterion is known to impact the biotic variable being used as an ecotoxicological indicator (e.g., nutrient ions).