Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
ACS Appl Mater Interfaces. 2023 Jul 12;15(27):32687-32696. doi: 10.1021/acsami.3c04311. Epub 2023 Jun 26.
The development of highly selective probes for nanoparticles is required due to their nanotoxicity. The latter strongly depends on the size, structure, and interfacial properties of the nanoparticles. Here, we demonstrate that a simple approach for the selective detection of Au nanoparticles that differ in their capping agent shows very high promise. Specifically, gold nanoparticles stabilized by each of the three different isomers of mercaptobenzoic acid (MBA) were imprinted in a soft matrix by adsorption of the nanoparticles, followed by filling the non-occupied areas through electropolyermization of an aryl diazonium salt (ADS). Nanocavities bearing the shape of the Au nanoparticles were formed upon the electrochemical dissolution of the nanoparticles, which were used for the reuptake of the Au nanoparticles stabilized by the different isomers. High reuptake selectivity was found where the originally imprinted nanoparticles were recognized better than the Au nanoparticles stabilized by other MBA isomers. Furthermore, an imprinted matrix by nanoparticles stabilized by 4-MBA could also recognize nanoparticles stabilized by 2-MBA, and vice versa. A detailed study using Raman spectroscopy and electrochemistry disclosed the organization of the capping isomers on the nanoparticles as well as the specific nanoparticle-matrix interactions that were responsible for the high reuptake selectivity observed. Specifically, the Raman band at ca. 910 cm for all AuNP-matrix systems implies the formation of a carboxylic acid dimer and thus the interaction of the ligands with the matrix. These results have implications for the selective and simple sensing of engineered nanoparticles.
由于纳米颗粒的纳米毒性，需要开发高选择性的纳米探针。后者强烈依赖于纳米颗粒的尺寸、结构和界面特性。在这里，我们证明了一种简单的方法可以选择性地检测不同封端剂的金纳米颗粒，具有很高的应用前景。具体来说，通过吸附纳米颗粒，在软基质中对三种不同异构体的巯基苯甲酸（MBA）稳定的金纳米颗粒进行印迹，然后通过芳基重氮盐（ADS）的电聚合填充非占据区域。在纳米颗粒的电化学溶解过程中形成了具有金纳米颗粒形状的纳米腔，用于不同异构体稳定的金纳米颗粒的再摄取。发现高再摄取选择性，其中最初印迹的纳米颗粒比由其他 MBA 异构体稳定的金纳米颗粒更好地被识别。此外，由 4-MBA 稳定的纳米颗粒印迹的基质也可以识别由 2-MBA 稳定的纳米颗粒，反之亦然。使用拉曼光谱和电化学进行的详细研究揭示了封端异构体在纳米颗粒上的组织以及负责观察到的高再摄取选择性的特定纳米颗粒-基质相互作用。具体来说，所有 AuNP-基质系统的约 910 cm 的拉曼带意味着羧酸二聚体的形成，从而导致配体与基质的相互作用。这些结果对于工程纳米颗粒的选择性和简单传感具有重要意义。
