Customizable Ligand Exchange for Tailored Surface Property of Noble Metal Nanocrystals
Customizable Ligand Exchange for Tailored Surface Property of Noble Metal Nanocrystals
复制标题
可定制的配体交换，用于定制贵金属纳米晶体的表面特性
DOI：
10.34133/2020/2131806
复制
发表时间：
2020-01-21
期刊：
影响因子：
11
通讯作者：
Gao, Chuanbo
中科院分区：
文献类型：
--
作者：
Fan, Qikui;Yang, Hao;Gao, Chuanbo
由于其胶体合成依赖于特定的旋盖配体来控制形状，而传统的配体交换过程存在“强取代弱”的限制，这极大地阻碍了其应用，因此获得具有定制旋盖配体的贵金属纳米晶体是非常理想的，但仍然具有挑战性。在此，我们报告了一种通用且有效的配体交换方法，该方法可以用几乎任何类型的配体取代贵金属纳米晶体的天然盖层配体，从而产生灵活定制的表面特性。关键是使用二乙胺作为中间配体，其与金属表面的结合亲和力可方便地切换。作为强配体，其原形能有效去除天然配体；当质子化时，它失去了它的结合亲和力，促进了新的配体，特别是弱配体在金属表面的吸附。通过这种方法，可以克服传统配体交换过程中的不可逆顺序。十六烷基三甲基铵、柠檬酸盐、聚乙烯吡咯烷酮和油胺之间的盖层配体相互交换证明了该策略的有效性。这种新策略极大地扩展了我们操纵贵金属纳米晶体表面特性的能力，并将其应用于广泛的领域，特别是生物医学应用。
It is highly desirable, while still challenging, to obtain noble metal nanocrystals with custom capping ligands, because their colloidal synthesis relies on specific capping ligands for the shape control while conventional ligand exchange processes suffer from “the strong replaces the weak” limitation, which greatly hinders their applications. Herein, we report a general and effective ligand exchange approach that can replace the native capping ligands of noble metal nanocrystals with virtually any type of ligands, producing flexibly tailored surface properties. The key is to use diethylamine with conveniently switchable binding affinity to the metal surface as an intermediate ligand. As a strong ligand, it in its original form can effectively remove the native ligands; while protonated, it loses its binding affinity and facilitates the adsorption of new ligands, especially weak ones, onto the metal surface. By this means, the irreversible order in the conventional ligand exchange processes could be overcome. The efficacy of the strategy is demonstrated by mutual exchange of the capping ligands among cetyltrimethylammonium, citrate, polyvinylpyrrolidone, and oleylamine. This novel strategy significantly expands our ability to manipulate the surface property of noble metal nanocrystals and extends their applicability to a wide range of fields, particularly biomedical applications.