Li Qiong, Zhang Jianan, Sun Wei, Yu Jiangbo, Wu Changfeng, Qin Weiping, Chiu Daniel T
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , Changchun, Jilin 130012, China.
Langmuir. 2014 Jul 22;30(28):8607-14. doi: 10.1021/la501876m. Epub 2014 Jul 9.
We report on a europium-complex-grafted polymer for preparing stable nanoparticle probes with high luminescence brightness, narrow emission bandwidth, and long luminescence lifetimes. A Eu complex bearing an amino group was used to react with a functional copolymer poly(styrene-co-maleic anhydride) by the spontaneous amidation reaction, producing the polymer grafted with Eu complexes in the side chains. The Eu-complex-grafted polymer was further used to prepare Eu-complex-grafted polymer dots (Pdots) and Eu-complex-blended poly(9-vinylcarbazole) composite Pdots, which showed improved colloidal stability as compared to those directly doped with Eu-complex molecules. Both types of Pdots can be efficiently quenched by a nile blue dye, exhibiting much lower detection limit and higher quenching sensitivity as compared to free Eu-complex molecules. Steady-state spectroscopy and time-resolved decay dynamics suggest the quenching mechanism is via efficient fluorescence resonance energy transfer from the Eu complex inside a Pdot to surface dye molecules. The amplified quenching in Eu-complex Pdots, together with efficient cell uptake and specific cell surface labeling observed in mammalian cells, suggests their potential applications in time-resolved bioassays and cellular imaging.
我们报道了一种用于制备具有高发光亮度、窄发射带宽和长发光寿命的稳定纳米颗粒探针的铕配合物接枝聚合物。使用带有氨基的铕配合物通过自发酰胺化反应与功能性共聚物聚（苯乙烯 - 马来酸酐）反应，在侧链上生成接枝有铕配合物的聚合物。铕配合物接枝聚合物进一步用于制备铕配合物接枝聚合物点（Pdots）和铕配合物共混的聚（9 - 乙烯基咔唑）复合Pdots，与直接掺杂铕配合物分子的那些相比，它们表现出更好的胶体稳定性。两种类型的Pdots都可以被尼罗蓝染料有效猝灭，与游离铕配合物分子相比，具有更低的检测限和更高的猝灭灵敏度。稳态光谱和时间分辨衰减动力学表明猝灭机制是通过从Pdot内部的铕配合物到表面染料分子的有效荧光共振能量转移。铕配合物Pdots中的放大猝灭，以及在哺乳动物细胞中观察到的有效细胞摄取和特异性细胞表面标记，表明它们在时间分辨生物测定和细胞成像中的潜在应用。
