Impact of Proteins on Aggregation Kinetics and Adsorption Ability of Hematite Nanoparticles in Aqueous Dispersions
Impact of Proteins on Aggregation Kinetics and Adsorption Ability of Hematite Nanoparticles in Aqueous Dispersions
复制标题
蛋白质对水分散体中赤铁矿纳米粒子聚集动力学和吸附能力的影响
DOI：
10.1021/acs.est.5b05298
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发表时间：
2016
影响因子：
11.4
通讯作者：
Juan Liu
中科院分区：
文献类型：
--
作者：
Anxu Sheng;Feng Liu;Nan Xie;Juan Liu
在pH 5.7和9的一价（NaCl）和二价（CaCl 2）电解质浓度范围内，研究了与两种模型球状蛋白质共轭的赤铁矿纳米颗粒（NPs）的初始聚集动力学. Cyt-NP缀合物的聚集行为类似于裸赤铁矿NP的聚集行为，但是额外的电空间排斥将pH 5.7的NaCl中的临界凝聚浓度（CCC）值从69 mM增加到113 mM。一个不饱和层的BSA，一种蛋白质大于细胞色素，赤铁矿纳米颗粒导致快速聚集在低盐浓度和pH值5.7，由于强大的吸引力的补丁电荷相互作用。然而，BSA-NP结合物可以简单地通过提高盐浓度来稳定，这是由于吸引性的补丁电荷力的屏蔽和空间位阻力的增加。该研究表明，蛋白质缀合的NPs的聚集状态被证明是通过离子强度、pH、蛋白质大小和蛋白质覆盖度完全可切换的。宏观Cu（II）吸附实验进一步确定，通过定制离子强度和蛋白质缀合来减少赤铁矿纳米颗粒的聚集可以促进赤铁矿纳米颗粒在苛刻条件下的金属吸收。
The initial aggregation kinetics of hematite nanoparticles (NPs) that were conjugated with two model globular proteinscytochrome c from bovine heart (Cyt) and bovine serum albumin (BSA)were investigated over a range of monovalent (NaCl) and divalent (CaCl2) electrolyte concentrations at pH 5.7 and 9. The aggregation behavior of Cyt-NP conjugates was similar to that of bare hematite NPs, but the additional electrosteric repulsion increased the critical coagulation concentration (CCC) values from 69 mM to 113 mM in NaCl at pH 5.7. An unsaturated layer of BSA, a protein larger than Cyt, on hematite NPs resulted in fast aggregation at low salt concentrations and pH 5.7, due to the strong attractive patch-charge interaction. However, the BSA-NP conjugates could be stabilized simply by elevating salt concentrations, owing to the screening of the attractive patch-charge force and the increasing contribution from steric force. This study showed that the aggregation state of protein-conjugated NPs is proved to be completely switchable via ionic strength, pH, protein size, and protein coverage. Macroscopic Cu(II) sorption experiments further established that reducing aggregation of hematite NPs via tailoring ionic strength and protein conjugation could promote the metal uptake by hematite NPs under harsh conditions.