Department of Electrical Engineering, University of Missouri, Columbia, MO 65211, USA.
Nanotechnology. 2012 May 4;23(17):175601. doi: 10.1088/0957-4484/23/17/175601. Epub 2012 Apr 5.
We report ultrabright, photostable, sub-25 nm nanoparticle agglomerates (suprananoparticles) assembled from a few hundred 3.3 ± 0.9 nm units, each hosting on average a single rhodamine 6G (Rh6G) dye molecule encased in a thin organosilicate cage. These individual Rh6G-doped nanoparticle (DOSNP) units consist of a hydrophobic core containing the dye and an ultrathin, conformal silicate shell modified by CO(2) plasma to confer a beneficial 'cage effect' as well as surface hydrophilicity. The isolation of the dye within individual DOSNP units in the final 22 ± 5 nm agglomerate avoids dimerization and related spontaneous molecular interactions that otherwise lead to self-quenching in closely co-localized fluorophores. The resulting suprananoparticles are over 200 times brighter than the free Rh6G molecules in the same volume. There is no observable dye leaching, and the labels are 20-fold more resistant to photobleaching than free Rh6G in solution. We demonstrate the attractive features of DOSNPs as labels in bioimaging applications.
我们报告了由几百个 3.3 ± 0.9 nm 的单元组装而成的超亮、光稳定、亚 25nm 的纳米颗粒聚集体（超纳米粒子），每个单元平均容纳一个单独的芘 6G（Rh6G）染料分子，封装在一个薄的有机硅酸盐笼中。这些单独的 Rh6G 掺杂纳米颗粒（DOSNP）单元由一个包含染料的疏水性核心和一个超薄的、共形的硅酸盐壳组成，壳经过 CO(2)等离子体修饰，赋予了有益的“笼效应”以及表面亲水性。在最终的 22 ± 5nm 聚集体中，染料被隔离在单个 DOSNP 单元内，避免了二聚化和相关的自发分子相互作用，否则这些相互作用会导致紧密共定位荧光团的自猝灭。由此产生的超纳米粒子比相同体积的游离 Rh6G 分子亮 200 多倍。没有观察到染料浸出，并且与游离 Rh6G 相比，标记在溶液中的光漂白抗性要强 20 倍。我们展示了 DOSNP 作为生物成像应用中的标签的吸引人的特性。
