title: Europium-complex-grafted polymer dots for amplified quenching and cellular imaging applications.
abstract: 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.
authors: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , Changchun, Jilin 130012, China.
authors: Qiong
authors: Q
authors: Li
authors: Jianan
authors: J
authors: Zhang
authors: Wei
authors: W
authors: Sun
authors: Jiangbo
authors: J
authors: Yu
authors: Changfeng
authors: C
authors: Wu
authors: Weiping
authors: W
authors: Qin
authors: Daniel T
authors: DT
authors: Chiu
mesh_terms: D005063:Europium / Q000737:chemistry*; D008298:Maleates / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry
chemical_list: D008298:Maleates; D011108:Polymers; D011137:Polystyrenes; C521900:poly(styrene-co-maleic anhydride); D005063:Europium