Ultrafast excited-state dynamics of nanoscale near-infrared emissive polymersomes.
Ultrafast excited-state dynamics of nanoscale near-infrared emissive polymersomes.
复制标题
DOI：
10.1021/ja711497w
复制
发表时间：
2008-07-30
影响因子：
15
通讯作者：
Therien MJ
中科院分区：
文献类型：
--
作者：
Duncan TV;Ghoroghchian PP;Rubtsov IV;Hammer DA;Therien MJ
通过两亲性二嵌段共聚物和电子共轭卟啉近红外（NIR）荧光团（NIRF）的协同自组装形成的NIR发射聚合物囊泡（直径为50 nm至50 μm的聚合物囊泡）定义了一系列基于有机的软物质结构，非常适合于深层组织光学成像和灵敏的诊断应用。在这里，我们描述魔角和偏振泵浦探测光谱实验：（i）探针聚合物体结构和NIRF组织和（ii）连接发射体结构特性和NIRF加载囊泡发射输出在纳米级。在聚合物囊泡膜环境中，长的聚合物链限制乙炔桥连的寡聚（卟啉）锌（II）为基础的超分子荧光团（PZnn）保形的人口和分散这些PZnn物种的疏水双层。超快激发态瞬态吸收和各向异性动力学研究的近红外发射聚合物囊泡，其中PZnn荧光团负载每纳米囊泡是0.1-10摩尔%之间变化，使浓度依赖性的非辐射激发态衰减机制的探索。这些实验将荧光团结构与其在这些纳米颗粒的特定纳米结构域内的总体空间排列相关联，并揭示了在减少的有效分散体积内荧光团的区室化如何影响本体物理性质。由于这些因素在确定分散的荧光团之间的能量转移动力学中起着关键作用，因此这项工作强调了调节荧光团和聚合物结构以优化双层纳米尺度囊泡环境中的分散体积的策略将进一步增强这些敏感的纳米尺度探针的发射特性。
Formed through cooperative self-assembly of amphiphilic diblock copolymers and electronically conjugated porphyrinic near-infrared (NIR) fluorophores (NIRFs), NIR-emissive polymersomes (50 nm to 50 μm diameter polymer vesicles) define a family of organic-based, soft-matter structures that are ideally suited for deep-tissue optical imaging and sensitive diagnostic applications. Here, we describe magic angle and polarized pump–probe spectroscopic experiments that: (i) probe polymersome structure and NIRF organization and (ii) connect emitter structural properties and NIRF loading with vesicle emissive output at the nanoscale. Within polymersome membrane environments, long polymer chains constrain ethyne-bridged oligo(porphinato)zinc(II) based supermolecular fluorophore (PZnn) conformeric populations and disperse these PZnn species within the hydrophobic bilayer. Ultrafast excited-state transient absorption and anisotropy dynamical studies of NIR-emissive polymersomes, in which the PZnn fluorophore loading per nanoscale vesicle is varied between 0.1–10 mol %, enable the exploration of concentration-dependent mechanisms for nonradiative excited-state decay. These experiments correlate fluorophore structure with its gross spatial arrangement within specific nanodomains of these nanoparticles and reveal how compartmentalization of fluorophores within reduced effective dispersion volumes impacts bulk photophysical properties. As these factors play key roles in determining the energy transfer dynamics between dispersed fluorophores, this work underscores that strategies that modulate fluorophore and polymer structure to optimize dispersion volume in bilayered nanoscale vesicular environments will further enhance the emissive properties of these sensitive nanoscale probes.
登录
查看更多内容
影响因子：
8.6
作者：
Ghoroghchian, P. Peter;Frail, Paul R.;Therien, Michael J.
通讯作者：
Therien, Michael J.
影响因子：
15
作者：
CARUSO, F;GRIESER, F;WISTUS, E
通讯作者：
WISTUS, E
影响因子：
7.4
作者：
Chinnayelka, S;McShane, MJ
通讯作者：
McShane, MJ
影响因子：
4.4
作者：
BOULU, LG;PATTERSON, LK;KOZAK, JJ
通讯作者：
KOZAK, JJ
影响因子：
56.9
作者：
Bruchez, M;Moronne, M;Alivisatos, AP
通讯作者：
Alivisatos, AP