The impact of iron (hydr)oxide adsorption on nucleotides and nucleic acids (NNA) in the environment varies. However, there is a lack of quantitative reports on how iron (hydr)oxide adsorption changes with different NNA structures. Here we examined NNAs with varying numbers of P-O(H) groups (including P-OH and P-O-, ranging from 2 to 4200-36000) and different nucleoside structures for their adsorption onto iron (hydr)oxide nanoparticles (i.e., goethite) at pH 7.0. The adsorption of NNA was driven by formation of Fe-O-P bonds, which could be hindered by the presence of phosphoric acid anion (PA) due to their overlapping adsorption sites on goethite. Analysis of OH- release during adsorption indicated that 2 to 2110-29600 P-O(H) groups in the NNA molecule were involved in Fe-O-P bonding, with the engagement increasing with the number of P-O(H) groups. The increase in P-O(H) groups in Fe-O-P bonding resulted in a two-step increase in adsorption strength (based on phosphorus atom). Initially, the adsorption strength was weaker than that of PA (for nucleoside monophosphates). Then it became comparable to PA (for nucleoside diphosphates and triphosphates), and eventually exceeded PA (for nucleic acids). The weaker affinity of the nucleoside moiety to goethite (in the case of nucleotides) and the hinderance of P-O(H) in forming Fe-O-P bonds due to molecular assembly and aggregation (for nucleic acids) reduced the adsorption enhancement through Fe-O-P bonding. These findings highlight the importance of both phosphate and non-phosphate structures in NNA adsorption, which can contribute to the assessment of environmental impacts of NNAs in iron-rich soil and water systems, particularly in relation to the phosphorus cycle and the spread of antibiotic resistance genes.

中文翻译：

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针铁矿纳米颗粒上核苷酸和核酸的吸附：模式、位点及其与磷酸盐和非磷酸盐结构的关系

（氢氧化）氧化铁吸附对环境中核苷酸和核酸 (NNA) 的影响各不相同。然而，目前缺乏关于不同 NNA 结构对氧化铁吸附如何变化的定量报告。在这里，我们检查了具有不同数量 PO(H) 基团（包括 P-OH 和 PO-，范围从 2 到 4200-36000）和不同核苷结构的 NNA 在氧化铁纳米颗粒（即针铁矿）上的吸附情况。 pH值7.0。 NNA 的吸附是由 Fe-OP 键的形成驱动的，由于它们在针铁矿上的吸附位点重叠，磷酸阴离子 (PA) 的存在可能会阻碍 Fe-OP 键的吸附。对吸附过程中OH-释放的分析表明，NNA分子中的2至2110-29600个PO(H)基团参与了Fe-OP键合，并且随着PO(H)基团数量的增加，结合量增加。 Fe-OP键合中PO(H)基团的增加导致吸附强度两步增加（基于磷原子）。最初，吸附强度弱于 PA（对于核苷单磷酸）。然后它变得与 PA（对于核苷二磷酸和三磷酸）相当，并最终超过 PA（对于核酸）。核苷部分与针铁矿的亲和力较弱（对于核苷酸而言）以及由于分子组装和聚集（对于核酸）而形成 Fe-OP 键的 PO(H) 的阻碍，降低了通过 Fe-OP 键合的吸附增强。这些发现强调了磷酸盐和非磷酸盐结构在 NNA 吸附中的重要性，这有助于评估 NNA 在富铁土壤和水系统中的环境影响，特别是与磷循环和抗生素耐药性传播相关的影响基因。