Institute of Chemistry, the Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
Nanoscale. 2016 Aug 7;8(29):13934-43. doi: 10.1039/c6nr01106c. Epub 2016 Mar 9.
The toxicity of nanoparticles is not only a function of the constituting material but depends largely on their size, shape and stabilizing shell. Hence, the speciation of nanoscale objects, namely, their detection and separation based on the different species, similarly to heavy metals, is of outmost importance. Here we demonstrate the speciation of gold nanoparticles (AuNPs) and their electrochemical detection using the concept of "nanoparticles imprinted matrices" (NAIM). Negatively charged AuNPs are adsorbed as templates on a conducting surface previously modified with polyethylenimine (PEI). The selective matrix is formed by the adsorption of either oleic acid (OA) or poly(acrylic acid) (PAA) on the non-occupied areas. The AuNPs are removed by electrooxidation to form complementary voids. These voids are able to recognize the AuNPs selectively based on their size. Furthermore, the selectivity could be improved by adsorbing an additional layer of 1-hexadecylamine, which deepened the voids. Interestingly, silver nanoparticles (AgNPs) were also recognized if their size matched those of the template AuNPs. The steps in assembling the NAIMs and the reuptake of the nanoparticles were characterized carefully. The prospects for the analytical use of NAIMs, which are simple, of small dimension, cost-efficient and portable, are in the sensing and separation of nanoobjects.
纳米粒子的毒性不仅是构成材料的函数，而且在很大程度上取决于其尺寸、形状和稳定壳。因此，纳米级物体的形态，即基于不同物种的检测和分离，类似于重金属，是至关重要的。在这里，我们展示了金纳米粒子 (AuNPs) 的形态和它们的电化学检测，使用“纳米粒子印迹基质” (NAIM) 的概念。带负电荷的 AuNPs 被吸附为模板，吸附在先前用聚乙烯亚胺 (PEI) 修饰的导电表面上。选择性基质是通过在非占据区域上吸附油酸 (OA) 或聚丙烯酸 (PAA) 形成的。AuNPs 通过电氧化去除以形成互补的空隙。这些空隙能够基于其尺寸选择性地识别 AuNPs。此外，通过吸附额外的一层 1-十六烷基胺，可以提高选择性，加深空隙。有趣的是，如果银纳米粒子 (AgNPs) 的尺寸与模板 AuNPs 匹配，它们也可以被识别。仔细描述了组装 NAIM 和重新吸收纳米粒子的步骤。NAIMs 的分析用途具有简单、尺寸小、成本效益高和便携性等优点，有望用于纳米物体的传感和分离。
