中文摘要：

基于荧光共振能量转移机理（FRET），利用两亲性聚合物Pluronic F-127共包覆两种聚集诱导发光（Aggregation-induced Emission，ALE）,材料TPABDFN和TPE—Me，制备了高效近红外发射TPABDFN／TPE-Me@F127纳米粒子．实验表明，这种聚合物纳米粒子具有很大的斯托克斯位移和较高的荧光量子效率，很好的单分散性、稳定性，以及较好的生物相容性和低的细胞毒性，对HepG2细胞进行荧光生物成像，得到很好的细胞成像效果．

英文摘要：

Near-infrared fluorescence signals are highly desirable to acheieve high resolution in biological imaging. We encapsulated hydrophobic AIE （aggregation-induced emission） fluorophores into the biocompatible Pluronic F-127 NPs for cellular imaging and efficiently enhance the near-infrared AIE fiuorophore emission. AIE molecule 2-（4-bromophenyl）-3- （4-（4-（diphenylamino）styryl）phenyl） fumaronitrile （TPABDFN） with near-infrared emission was synthesized and selected as the fluorescence resonance energy transfer （FRET） acceptor. （2-p-tolylethene-l,l,2-triyl）tribenzene （TPE-Me） was a blue-emitting AIE molecule, which spectrum was matching with TPABDFN. TPE-Me@F127 NPs emission was 480 nm, TPABDFN@F127 NPs maximum absorption wavelength was also 480 nm, that the absorption had a large area of overlap- ping with the TPE-Me@F127 NPs emission spectrum and leaded to efficient energy transfer, so TPE-Me was selected as the FRET donor. By encapsulating both TPE-Me donor and TPABDFN acceptor simultaneously within the NPs, a significant FRET effect was induced. FRET pairs of different ratios was co-encapsulated into the F127 NPs to optimize the fluorescence signals. The maximum of fluorescence quantum yield was 19.9%, energy transfer efficiency was 43.5%. TPABDFN@FI27 NPs only had weak fluorescence, but the TPABDFN/TPE-Me@F127 NPs showed bright fluorescence signal. Fluorescence resonance energy transfer contributed to the notable increase of aceeptor emission The fluorescence quantum yield had 10-fold enhancement of the TPABDFN. In addition, the obtained TPABDFN/TPE-Me@F127 NPs showed a large Stokes shift of 265 nm, which can be used to avoid the interference between excitation and emission light, as well as the near-infrared emission spectrum away from the organism auto-fluorescence, which was beneficial for the bio-application. Fluorescent probe emission in the far red/near-infrared （FR/NIR） （650~900 nm） region for biological detection also can greatly reduce the damage to living body.