Department of Biomedical Engineering, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China.
Langmuir. 2013 Aug 27;29(34):10907-14. doi: 10.1021/la401999r. Epub 2013 Aug 14.
In this paper, we report on the versatile self-assembly of water-soluble thiol-capped CdTe quantum dots (QDs), nanoparticles (NPs), or nanocrystals induced by L-cysteine (L-Cys). Major efforts are focused on the control of the self-organization of QDs into nanosheets (NSs), for example, by altering the solution pH and the QD size. The as-prepared nanosheets exhibit bright photoluminescence (PL) and retain the size-quantized properties of initial CdTe QDs, since they are actually formed by a 2D network of assembled QDs. By optical techniques, TEM, EDX, powder XRD, etc., it is found that the unique L-Cys-induced external destabilization is responsible for the template-free self-organization process, with the further assistance of the specific NP-NP interactions. And the internal chemical stability of initial CdTe QDs also is proven for the first time to play an important role. These results help to enhance the current understanding about the mechanism for the destabilization of colloidal NPs and their self-assembly behavior.
在本文中，我们报告了水溶性巯基封端的 CdTe 量子点（QDs）、纳米粒子（NPs）或纳米晶体通过 L-半胱氨酸（L-Cys）的多功能自组装。主要努力集中在控制 QDs 自组装成纳米片（NSs），例如，通过改变溶液 pH 值和 QD 尺寸。所制备的纳米片表现出明亮的光致发光（PL），并保留初始 CdTe QDs 的尺寸量化特性，因为它们实际上是由组装 QDs 的二维网络形成的。通过光学技术、TEM、EDX、粉末 XRD 等，发现独特的 L-Cys 诱导的外部失稳是无模板自组装过程的原因，而特定的 NP-NP 相互作用也提供了进一步的帮助。并且，初始 CdTe QDs 的内部化学稳定性也首次被证明起到了重要作用。这些结果有助于增强对胶体 NPs 失稳及其自组装行为机制的现有理解。
