Nanomaterial-Agrichemical Interactions: Association of Environmental Herbicides With Two-Dimensional Graphene Nanoplatelets

摘要

Atrazine and glyphosate are the two most common agricultural herbicides used in the United States. Both herbicides can move in the environment, which results in contamination of drinking water sources. Graphene nanoplatelets (GNPs) are an emerging nanoparticle with potential uses for the remediation of environmental contamination. The first aim of this study was to determine binding interactions between atrazine and GNPs to mimic a mixture composition. To determine binding interactions, GNPs with different functional groups (none, carboxylated, or aminylated) were evaluated. GNPs at concentrations of 0, 0.5, 1, 2, or 3 mg/ml were incubated with atrazine at 3 ppb (μg/L) and centrifuged, allowing a supernatant to be collected. The supernatant was used to quantify the concentration of atrazine using an Abraxis Atrazine ELISA assay. The data demonstrated that as the concentration of GNPs increased, the percentage of atrazine bound increased until it plateaued at 2–3 mg/ ml of GNPs. The nonfunctionalized GNPs (N-GNPs) bound the most atrazine compared to the functionalized GNPs. The final aim of this study was to determine whether GNPs can be used as a tool for environmental remediation of atrazine and glyphosate contamination. Mixtures involving N-GNPs (1 mg/ml) and the herbicides atrazine (3 ppb) and glyphosate (700 ppb) were created to mimic environmental conditions. The mixtures were treated with a similar protocol as the first aim. This experiment demonstrated that N-GNPs bind to atrazine, while binding does not occur between glyphosate and N-GNPs. In addition, glyphosate did not interfere with the binding between atrazine and N-GNPs.