Copper oxide nanoparticle dissolution at alkaline pH is controlled by dissolved organic matter: influence of soil-derived organic matter, wheat, bacteria, and nanoparticle coating
Copper oxide nanoparticle dissolution at alkaline pH is controlled by dissolved organic matter: influence of soil-derived organic matter, wheat, bacteria, and nanoparticle coating
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氧化铜纳米颗粒在碱性pH下的溶解受溶解有机物控制：土源有机物、小麦、细菌和纳米颗粒涂层的影响
DOI：
10.1039/d0en00574f
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发表时间：
2020-09-01
影响因子：
7.3
通讯作者：
McLean, J. E.
中科院分区：
文献类型：
--
作者：
Hortin, J. M.;Anderson, A. J.;McLean, J. E.
CuO 纳米粒子溶解并释放出 Cu 离子，是植物根区 Cu 相互作用的主要机制。 CuO 的溶解有时被错误地认为在高 pH 值下可以忽略不计，因为 Cu 与溶解的有机物的络合可能会增强纳米颗粒的溶解。因此，需要有关植物-微生物-土壤相互作用对纳米颗粒溶解影响的数据，特别是在碱性土壤中。研究了 CuO 纳米粒子（100 mg kg(-1)Cu）在沙子中的溶解情况，沙子中添加了小麦生长、根部定殖细菌和来自三种碱性钙质土壤的饱和糊状提取物 (SPE) 的因子组合。在含有 3.34 mM Ca(NO3)(2) 溶液的对照砂体系中，溶解的 Cu 较低（266 μg L-1Cu）。通过小麦根代谢物和/或土壤 SPE 添加溶解有机物，可将溶解铜增加至 795-6250 mu g L-1Cu。溶解度与溶解的有机碳相关（R= 0.916，p<0.0001）。配体 >3 kDa，可能是来自 SPE 的黄腐酸，络合 Cu 驱动溶解度；植物分泌物的添加进一步将溶解度提高了 1.5-3.5 倍。由于根系分泌物的代谢，根部定殖细菌减少了种植系统沙孔水中溶解的铜。使用土壤固相萃取物和含有碳酸氢盐或黄腐酸的规定溶液进行批量溶解度研究（10 mg L-1Cu），证实了 CuO 纳米颗粒在 pH 值 >7.5 时溶解度升高。与沙子、维亚纳米粒子有机物涂层或溶解的有机物的同共轭相比，在批量实验中纳米粒子的溶解受到抑制。土壤有机质、植物分泌物和细菌对 CuO 纳米颗粒的改变将影响 CuO 纳米颗粒在碱性土壤中的溶解和生物利用度。
Dissolution of CuO nanoparticles, releasing Cu ions, is a primary mechanism of Cu interaction in the rooting zone of plants. CuO dissolution is sometimes incorrectly considered negligible at high pH, since complexation of Cu with dissolved organic matter may enhance nanoparticle dissolution. Therefore data on the effects of plant-microbial-soil interactions on nanoparticle dissolution, particularly in alkaline soils, are needed. Dissolution of CuO nanoparticles (100 mg kg(-1)Cu) was studied in sand supplemented with factorial combinations of wheat growth, a root-colonizing bacterium, and saturated paste extracts (SPEs) from three alkaline, calcareous soils. In control sand systems with 3.34 mM Ca(NO3)(2)solution, dissolved Cu was low (266 mu g L-1Cu). Addition of dissolved organic matterviawheat root metabolites and/or soil SPEs increased dissolved Cu to 795-6250 mu g L-1Cu. Dissolution was correlated with dissolved organic carbon (R= 0.916,p< 0.0001). Ligands >3 kDa, presumably fulvic acid from the SPEs, complexed Cu driving solubility; the addition of plant exudates further increased solubility 1.5-3.5x. The root-colonizing bacterium decreased dissolved Cu in sand pore waters from planted systems due to metabolism of root exudates. Batch solubility studies (10 mg L-1Cu) with the soil SPEs and defined solutions containing bicarbonate or fulvic acid confirmed elevated CuO nanoparticle solubility at >7.5 pH. Nanoparticle dissolution was suppressed in batch experiments compared to sand,viananoparticle organic matter coating or homoconjugation of dissolved organic matter. Alterations of CuO nanoparticles by soil organic matter, plant exudates, and bacteria will affect dissolution and bioavailability of the CuO nanoparticles in alkaline soils.