Photoligation of an amphiphilic polymer with mixed coordination provides compact and reactive quantum dots.
Photoligation of an amphiphilic polymer with mixed coordination provides compact and reactive quantum dots.
复制标题
DOI：
10.1021/jacs.5b00671
复制
发表时间：
2015
影响因子：
15
通讯作者：
Wentao Wang;Anshika Kapur;X. Ji;M. Safi;G. Palui;V. Palomo;P. Dawson;H. Mattoussi
中科院分区：
文献类型：
--
作者：
Wentao Wang;Anshika Kapur;X. Ji;M. Safi;G. Palui;V. Palomo;P. Dawson;H. Mattoussi
我们引入了一组新的多配位聚合物作为配体，结合了两个不同的金属螯合基团，硫辛酸和咪唑，用于量子点的表面功能化。这些配体结合了硫醇和咪唑配位的优点，减少了硫醇氧化和咪唑的弱结合亲和力问题。配体设计依赖于通过一步亲核加成反应将可控数量的硫辛酸和组胺锚点，以及亲水部分和活性官能团引入聚（异丁烯-马来酸酐）链上。我们进一步证明，这种设计完全兼容一种新的和温和的光化策略，以促进疏水量子点在无硼氢化物条件下的原位配体交换和相转移到水介质中。与这些聚合物的连接提供了高荧光量子点，在广泛的条件下，包括广泛的pH范围（3-13），以纳摩尔浓度储存，在环境条件下，在100%生长介质中，以及在具有强还原性的竞争剂存在下，表现出长期的胶体稳定性。我们进一步表明，在配体中加入活性基团允许荧光染料和氧化还原活性多巴胺与量子点共价结合，产生荧光平台，其中发射通过Förster共振能量转移（FRET）或ph依赖电荷转移（CT）相互作用控制/调节。最后，聚合物包被的量子点与细胞穿透肽偶联以促进细胞内摄取，而随后的细胞毒性测试显示细胞活力没有明显下降。
We introduce a new set of multicoordinating polymers as ligands that combine two distinct metal-chelating groups, lipoic acid and imidazole, for the surface functionalization of QDs. These ligands combine the benefits of thiol and imidazole coordination to reduce issues of thiol oxidation and weak binding affinity of imidazole. The ligand design relies on the introduction of controllable numbers of lipoic acid and histamine anchors, along with hydrophilic moieties and reactive functionalities, onto a poly(isobutylene-alt-maleic anhydride) chain via a one-step nucleophilic addition reaction. We further demonstrate that this design is fully compatible with a novel and mild photoligation strategy to promote the in situ ligand exchange and phase transfer of hydrophobic QDs to aqueous media under borohydride-free conditions. Ligation with these polymers provides highly fluorescent QDs that exhibit great long-term colloidal stability over a wide range of conditions, including a broad pH range (3-13), storage at nanomolar concentration, under ambient conditions, in 100% growth media, and in the presence of competing agents with strong reducing property. We further show that incorporating reactive groups in the ligands permits covalent conjugation of fluorescent dye and redox-active dopamine to the QDs, producing fluorescent platforms where emission is controlled/tuned by Förster Resonance Energy Transfer (FRET) or pH-dependent charge transfer (CT) interactions. Finally, the polymer-coated QDs have been coupled to cell-penetrating peptides to facilitate intracellular uptake, while subsequent cytotoxicity tests show no apparent decrease in cell viability.