Chen Yue, Cordero Jose M, Wang Hua, Franke Daniel, Achorn Odin B, Freyria Francesca S, Coropceanu Igor, Wei He, Chen Ou, Mooney David J, Bawendi Moungi G
Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA.
John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford St., Cambridge, MA, 02138, USA.
Angew Chem Int Ed Engl. 2018 Apr 16;57(17):4652-4656. doi: 10.1002/anie.201801113. Epub 2018 Mar 13.
We present a novel ligand, 5-norbornene-2-nonanoic acid, which can be directly added during established quantum dot (QD) syntheses in organic solvents to generate "clickable" QDs at a few hundred nmol scale. This ligand has a carboxyl group at one terminus to bind to the surface of QDs and a norbornene group at the opposite end that enables straightforward phase transfer of QDs into aqueous solutions via efficient norbornene/tetrazine click chemistry. Our ligand system removes the traditional ligand-exchange step and can produce water-soluble QDs with a high quantum yield and a small hydrodynamic diameter of approximately 12 nm at an order of magnitude higher scale than previous methods. We demonstrate the effectiveness of our approach by incubating azido-functionalized CdSe/CdS QDs with 4T1 cancer cells that are metabolically labeled with a dibenzocyclooctyne-bearing unnatural sugar. The QDs exhibit high targeting efficiency and minimal nonspecific binding.
我们展示了一种新型配体，5-降冰片烯-2-壬酸，它可以在有机溶剂中已有的量子点（QD）合成过程中直接添加，以几百纳摩尔的规模生成“可点击”的量子点。该配体一端有一个羧基用于结合量子点表面，另一端有一个降冰片烯基团，通过高效的降冰片烯/四嗪点击化学实现量子点向水溶液的直接相转移。我们的配体系统省去了传统的配体交换步骤，并且能够以比以前方法高一个数量级的规模，生产出具有高量子产率和大约12纳米的小流体动力学直径的水溶性量子点。我们通过将叠氮基功能化的CdSe/CdS量子点与用含二苯并环辛炔的非天然糖进行代谢标记的4T1癌细胞孵育，证明了我们方法的有效性。这些量子点表现出高靶向效率和最小的非特异性结合。
