Few standardized methods and reference systems have been established for evaluating the behavior of engineered nanomaterials in complex media like natural soils. In this study, a working method for a functional assay to determine the affinity of nanoparticles (NPs) for soil surfaces by batch test is provided along with a case study demonstrating the utility of the method using a proposed reference soil (LUFA 2.2) and gold nanoparticles (AuNPs) with four different surface treatments (citrate [Cit], gum arabic [GA], polyvinylpyrrolidone [PVP], and branched polyethylenimine [bPEI]). Particle attachment efficiencies (α) of AuNPs with LUFA 2.2 soil spanned four orders of magnitude, with α_bPEI-Au > α_PVP-Au > α_Cit-Au ≫ α_GA-Au, suggesting that GA-Au will be significantly more mobile in this soil than the other AuNPs. These results run counter to a widely held assumption that acquired macromolecular coatings in natural systems will likely mask engineered coatings and dictate NP mobility. Moreover, the trend in attachment efficiency could not be predicted based on differences in intrinsic or extrinsic NP properties alone, which supports the need for development and validation of well-controlled functional assays performed in complex media.

中文翻译：

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纳米粒子对天然土壤的亲和力：用于测定复杂系统中粒子附着效率的功能测定

很少建立标准化的方法和参考系统来评估工程纳米材料在复杂介质（如天然土壤）中的行为。在这项研究中，提供了一种用于通过批处理测试确定纳米颗粒（NPs）对土壤表面亲和力的功能测定的工作方法，以及一个案例研究，该案例表明了使用建议的参考土壤（LUFA 2.2）和金的方法的实用性纳米粒子（AuNPs）具有四种不同的表面处理（柠檬酸盐[Cit]，阿拉伯树胶[GA]，聚乙烯吡咯烷酮[PVP]和支链聚乙烯亚胺[bPEI]）。粒子的附着效率（α与LUFA金纳米粒子）2.2土壤跨越四个数量级，与α _BPEI金> α _PVP金> α_CIT-金» α _GA-金，这表明GA-金将在这片土壤比其他金纳米显著更多的移动。这些结果与普遍持有的假设相反，即自然系统中获得的高分子涂层可能会掩盖工程涂层并决定NP的迁移率。此外，不能仅基于内在或外在NP特性的差异来预测附着效率的趋势，这支持了开发和验证在复杂介质中进行的功能良好的功能测定的需求。