Natural organic matter composition determines the molecular nature of silver nanomaterial-NOM corona
Natural organic matter composition determines the molecular nature of silver nanomaterial-NOM corona
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DOI：
10.1039/c8en00018b
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发表时间：
2018-04-01
影响因子：
7.3
通讯作者：
Guo, Laodong
中科院分区：
文献类型：
--
作者：
Baalousha, Mohammed;Afshinnia, Kamelia;Guo, Laodong
天然有机物（NOM）在纳米材料（NMs）上的吸附导致NMs与周围环境之间形成界面区域（称为NOM-corona），从而产生NMs独特的表面特性。这种独特的表面特性是由配体及其与 NM 表面的相互作用决定的。由于化学结构和功能是异质和多分散的，NOM-corona的分子组成是NOM分子在NM表面上竞争吸附的结果。在这里，我们使用电喷雾电离-傅里叶变换离子回旋共振质谱 (ESI-FT-ICR-MS) 研究了 AgNM 表面上两个不同 NOM 样品（从育空河和密尔沃基河分离）形成的 NOM-corona 的分子组成。 AgNM-NOM 电晕的组成随原始 NOM 的组成而变化。一般来说，AgNM-NOM 电晕富含含氮和含硫化合物。此外，AgNM-NOM 冠富含高分子量、高不饱和度和大量含氧基团的化合物。然而，育空河 NOM 的 AgNM 上吸附的 CHOS（碳、氢、氧和硫）化合物具有低分子量（LMW）和低饱和指数，这可能是由于通过化学络合（Ag-S）进行选择性吸附所致。另一方面，具有LMW和低不饱和度的NOM化合物或含有少量含氧基团（主要是醇和醚）的化合物优先保持在溶液相中。这里的结果提供了 NOM 和 NM 之间分子相互作用的证据，这对于理解 NM 在自然环境中的行为和毒性至关重要。
Adsorption of natural organic matter (NOM) on nanomaterials (NMs) results in the formation of interfacial area between NMs and the surrounding environment (referred to as NOM-corona), giving rise to NMs' unique surface identity. This unique surface identity is determined by the ligands and their interactions with NM surfaces. Since the chemical structure and functionality is heterogeneous and polydisperse, the molecular composition of NOM-corona is the result of competitive adsorption of NOM molecules on the NM surface. Here, we investigate the molecular composition of NOM-corona formed from two different NOM samples (isolated from the Yukon River and Milwaukee River) on the surface of AgNMs using electrospray ionization-Fourier-transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). The composition of AgNM-NOM corona varied with the composition of the original NOM. In general, AgNM-NOM corona is rich with N-and S-containing compounds. Furthermore, AgNM-NOM corona is rich with compounds with high molecular weight, high unsaturation, and high number of oxygenated groups. However, CHOS (carbon, hydrogen, oxygen and sulfur) compounds adsorbed on AgNMs from the Yukon River NOM have low molecular weight (LMW) and low saturation index, which might be due to selective adsorption via chemical complexation (Ag-S). On the other hand, NOM compounds with LMW and low unsaturation or compounds containing few oxygenated groups (mainly alcohols and ethers) are preferentially maintained in solution phase. The results here provide evidence of molecular interactions between NOM and NMs, which are critical to understanding NM behavior and toxicity in natural environments.