Efficient, stable, small, and water-soluble doped ZnSe nanocrystal emitters as non-cadmium biomedical labels
Efficient, stable, small, and water-soluble doped ZnSe nanocrystal emitters as non-cadmium biomedical labels
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DOI：
10.1021/nl062336y
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发表时间：
2007-02-01
期刊：
影响因子：
10.8
通讯作者：
Peng, Xiaogang
中科院分区：
文献类型：
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作者：
Pradhan, Narayan;Battaglia, David M.;Peng, Xiaogang
通过用巯基丙酸（一种非常短的亲水性硫醇）单层涂覆具有可调光致发光（PL）峰位置的Mn 2+掺杂的ZnSe量子点（Mn：ZnSe d-点）使其成为水溶性的。如果掺杂剂中心位于靠近表面，硫醇涂层部分淬灭PL。在表面上具有约2-3个纯ZnSe单层的情况下，d-点的PL实际上在硫醇涂覆后增强。当掺杂中心合理地放置在d-点内部时，掺杂中心和表面配体之间具有约四个纯ZnSe单层，硫醇配体不猝灭d-点的PL，即使它们完全猝灭本征ZnSe量子点的PL。这种d-dots/配体复合物的总尺寸仅为约7-8 nm，这意味着在生物问题中具有优异的渗透性。发现这些d-点在空气中对连续紫外线辐射特别稳定至少25天。它们在沸水中也是稳定的，在室内光照下空气冒泡数小时。识别的生物素图案的d-点与抗生物素蛋白缀合进行说明这些有效的（约40%的PL量子产率），稳定的，小的，和水溶性的d-点作为生物医学标记试剂的适用性。
Mn2+-doped ZnSe quantum dots (Mn:ZnSe d-dots) with a tunable photoluminescence (PL) peak position were made to be water soluble by coating them with a monolayer of mercaptopropionic acid, a very short hydrophilic thiol. If the dopant centers were located close to the surface, thiol-coating partially quenched the PL. With about 2-3 monolayers of pure ZnSe on the surface, the PL of d-dots was actually enhanced upon thiol coating. When the doping centers were placed reasonably inside a d-dot, with about four monolayers of pure ZnSe between the doping centers and the surface ligands, the thiol ligands did not quench the PL of the d-dots, even though they did completely quench the PL of intrinsic ZnSe quantum dots. The overall size of such d-dots/ligand complex is only about 7-8 nm, implying an excellent permeability in biological issues. These d-dots were found to be exceptionally stable against continuous UV radiation in air for at least 25 days. They were also stable in boiling water with air bubbling under room light for hours. Recognition of a biotin pattern by d-dots conjugated with avidine was carried to illustrate the suitability of these efficient (about 40% PL quantum yield), stable, small, and water-soluble d-dots as biomedical labeling reagents.