Natural organic matter composition and nanomaterial surface coating determine the nature of platinum nanomaterial-natural organic matter corona

Mohammed Baalousha; Mithun Sikder; Brett A Poulin; Malak M Tfaily; Nancy J Hess

doi:10.1016/j.scitotenv.2021.150477

Natural organic matter composition and nanomaterial surface coating determine the nature of platinum nanomaterial-natural organic matter corona

Sci Total Environ. 2022 Feb 1;806(Pt 1):150477. doi: 10.1016/j.scitotenv.2021.150477. Epub 2021 Sep 20.

Authors

Mohammed Baalousha¹, Mithun Sikder², Brett A Poulin³, Malak M Tfaily⁴, Nancy J Hess⁵

Affiliations

¹ South Carolina SmartState Center for Environmental Nanoscience and Risk (CENR), Department of Environmental Health Sciences, University of South Carolina, Columbia, SC 29208, USA. Electronic address: mbaalous@mailbox.sc.edu.
² South Carolina SmartState Center for Environmental Nanoscience and Risk (CENR), Department of Environmental Health Sciences, University of South Carolina, Columbia, SC 29208, USA.
³ U. S. Geological Survey, Boulder, CO 80303, USA; Department of Environmental Toxicology, University of California Davis, Davis, CA 95616, USA.
⁴ Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA; Department of Environmental Science, University of Arizona, AZ, USA 85721.
⁵ Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA.

PMID: 34563904
DOI: 10.1016/j.scitotenv.2021.150477

Abstract

Natural organic matter corona (NOM corona) is an interfacial area between nanomaterials (NMs) and the surrounding environment, which gives rise to NMs' unique surface identity. While the importance of the formation of natural organic matter (NOM) corona on engineered nanomaterials (NMs) to NM behavior, fate, and toxicity has been well-established, the understanding of how NOM molecular properties affect NOM corona composition remains elusive due to the complexity and heterogeneity of NOM. This is further complicated by the variation of NOMs from different origins. Here we use eight NOM isolates of different molecular composition and ultrahigh resolution Fourier-transform ion cyclotron resonance-mass spectrometry (ESI-FT-ICR-MS) to determine the molecular composition of platinum NM-NOM corona as a function of NOM composition and NM surface coating. We observed that the composition of PtNM-NOM corona varied with the composition of the original NOM. The percentage of NOM formulas that formed PVP-PtNM-NOM corona was higher than those formed citrate-PtNM-NOM corona, due to increased sorption of NOM formulas, in particular condensed hydrocarbons, to the PVP coating. The relative abundance of heteroatom formulas (CHON, CHOS, and CHOP) was higher in the PVP-PtNM-NOM corona than in citrate-PtNM-corona which was in turn higher than those in the original NOM isolate, indicating preferential partitioning of heteroatom-rich molecules to NM surfaces. The relative abundance of CHO, CHON, CHOS, CHOP and condensed hydrocarbons in PtNM-NOM corona increased with their increase in NOM isolates. Furthermore, PtNM-NOM corona is rich with compounds with high molecular weight. This study demonstrates that the composition and properties of PtNM-NOM corona depend on NOM molecular properties and PtNM surface coating. The results here provide evidence of molecular interactions between NOM and NMs, which are critical to understanding NM colloidal properties (e.g., surface charge and stability), interaction forces (e.g., van der Waals and hydrophobic), environmental behaviors (e.g., aggregation, dissolution, sulfidation, etc.), and biological effects (e.g., uptake, bioaccumulation, and toxicity).

Keywords: Corona; Molecular properties; Nanomaterials; Natural organic matter; Platinum; Surface coating.

MeSH terms

Hydrophobic and Hydrophilic Interactions
Mass Spectrometry
Nanostructures*
Platinum*

Substances

Platinum