State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China.
University of Chinese Academy of Sciences , Beijing 100190 , China.
Anal Chem. 2020 Jan 21;92(2):1948-1955. doi: 10.1021/acs.analchem.9b04262. Epub 2020 Jan 8.
Detection and quantification of carbon nanomaterials are extremely challenging, especially under the background interference of carbon. Here, we propose a new label-free method to quantify, track, and in situ image graphene and graphene oxide (GO) in plants based on their inherent metallic impurities as fingerprints. We show the ubiquity and high stability of inherent metallic fingerprints of graphene and GO obtained from different exposure routes under the natural environments, which enables the materials to be easily quantified and in situ imaged by high-sensitivity (laser ablation) inductively coupled plasma mass spectrometry. The method was applied to investigate the uptake and spatial distribution of graphene and GO in soybean plants. The plants were cultivated in graphene or GO solutions for 7 days, and the indicative elements (Ni or Mn) in different parts of plants were monitored and imaged. We found that graphene and GO showed different distribution patterns in plants (the highest uptake percentages in root up to 14.4% for graphene and 47.8% for GO), and high concentration of material exposure might cause excessive accumulation of materials in roots which blocked their further transport to the other parts of plants. The present method is more straightforward, accessible, and economical than normally used isotopic or metal-labeling methods. It also avoids the uncertainties or alterations of properties caused by the labeling process and thus has great promise in analysis and risk assessment of carbon nanomaterials.
碳纳米材料的检测和定量分析极具挑战性，尤其是在碳的背景干扰下。在这里，我们提出了一种新的无标记方法，基于其作为指纹的固有金属杂质来定量、跟踪和原位成像植物中的石墨烯和氧化石墨烯（GO）。我们展示了在自然环境下，通过不同暴露途径获得的石墨烯和 GO 的固有金属指纹的普遍性和高稳定性，这使得材料能够通过高灵敏度（激光烧蚀）电感耦合等离子体质谱法进行轻松定量和原位成像。该方法被应用于研究石墨烯和 GO 在大豆植株中的吸收和空间分布。将植物在石墨烯或 GO 溶液中培养 7 天，监测和成像植物不同部位的指示元素（Ni 或 Mn）。我们发现，石墨烯和 GO 在植物中表现出不同的分布模式（在根部的最高吸收率分别达到 14.4%的石墨烯和 47.8%的 GO），而高浓度的材料暴露可能导致材料在根部过度积累，从而阻止其进一步向植物的其他部位运输。与通常使用的同位素或金属标记方法相比，本方法更直接、更易于获取且更经济。它还避免了标记过程中产生的不确定性或性质改变，因此在分析和评估碳纳米材料的风险方面具有很大的应用前景。
