High-intensity near-IR fluorescence in semiconducting polymer dots achieved by cascade FRET strategy.
High-intensity near-IR fluorescence in semiconducting polymer dots achieved by cascade FRET strategy.
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DOI：
10.1039/c3sc50222h
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发表时间：
2013-05-01
期刊：
影响因子：
8.4
通讯作者：
Uvdal K
中科院分区：
文献类型：
--
作者：
Zhang X;Yu J;Rong Y;Ye F;Chiu DT;Uvdal K
具有超亮荧光的近红外 (NIR) 发射半导体聚合物点 (Pdot) 已被制备用于特定的细胞靶向。通过超声辅助共沉淀法合成了一系列π-共轭聚合物以形成水分散性多组分Pdot。通过优化 Pdot 中的级联能量转移，实现了具有可调谐激发的高强度 NIR 荧光 (φ = 0.32)、大吸收-发射分离 (高达 330 nm) 和窄发射带 (FWHM = 44 nm)。单颗粒荧光成像表明，在相同的激发和检测条件下，所制备的 NIR Pdot 比尺寸相当的市售 Qdot705 亮三倍以上。由于羧酸基团共价引入到聚合物侧链中，近红外发射P点和链霉亲和素之间的生物共轭可以通过P点表面上的这些官能团轻松完成。此外，通过流式细胞术和共聚焦荧光显微镜，近红外发射的 Pdot-链霉亲和素缀合物证明，它们可以通过链霉亲和素和生物素之间的特异性结合，有效地标记 MCF-7 细胞表面的 EpCAM 受体。
Near-IR (NIR) emitting semiconducting polymer dots (Pdots) with ultrabright fluorescence have been prepared for specific cellular targeting. A series of π-conjugated polymers were synthesized to form water dispersible multicomponent Pdots by an ultrasonication-assisted co-precipitation method. By optimizing cascade energy transfer in Pdots, high-intensity NIR fluorescence (φ = 0.32) with tunable excitations, large absorption–emission separation (up to 330 nm), and narrow emission bands (FWHM = 44 nm) have been achieved. Single-particle fluorescence imaging show that the as-prepared NIR Pdots were more than three times brighter than the commercially available Qdot705 with comparable sizes under identical conditions of excitation and detection. Because of the covalent introduction of carboxylic acid groups into polymer side chains, the bioconjugation between NIR-emitting Pdots and streptavidins can be readily completed via these functional groups on the surface of Pdots. Furthermore, through flow cytometry and confocal fluorescence microscopy the NIR-emitting Pdot–streptavidin conjugates proved that they could effectively label EpCAM receptors on the surface of MCF-7 cells, via specific binding between streptavidin and biotin.