Europium-Complex-Grafted Polymer Dots for Amplified Quenching and Cellular Imaging Applications

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• 作者：Qiong Li ; Jianan Zhang ; Wei Sun ; Jiangbo Yu ; Changfeng Wu ; Weiping Qin ; Daniel T. Chiu
• 刊名：Langmuir
• 出版年：2014
• 出版时间：July 22, 2014
• 年：2014
• 卷：30
• 期：28
• 页码：8607-8614
• 全文大小：438K
• ISSN：1520-5827

文摘

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.