Manipulating Nonradiative Decay Channel by Intermolecular Charge Transfer for Exceptionally Improved Photothermal Conversion
Manipulating Nonradiative Decay Channel by Intermolecular Charge Transfer for Exceptionally Improved Photothermal Conversion
复制标题
通过分子间电荷转移操纵非辐射衰变通道以显着改善光热转换
DOI：
10.1021/acsnano.9b06208
复制
发表时间：
2019-10-01
期刊：
影响因子：
17.1
通讯作者：
Prasad, Paras N.
中科院分区：
文献类型：
--
作者：
Hu, Wenbo;Miao, Xiaofei;Prasad, Paras N.
深入研究非辐射（NR）衰变，寻求最大化NR衰变速率或操纵其他NR衰变通道，对于提高光疗用有机材料的光热转换效率（eta）具有重要意义；然而，到目前为止，相关的工作仍然很少。在这里，我们提出了一项有见地的研究，在BODIPY （BDP）染料中，在聚集状态下，即在BDP纳米颗粒（BDP NPs）中，显示出来自聚集稳定的分子间电荷转移（CT）状态的有效的额外NR衰变通道，导致体内高效光治疗的异常高的eta（61%）。BDP NPs表现出两个超快NR衰减通道，寿命分别为1.7和50 ps，这与分离的BDP染料中仅有的S-1 -> S-0 NR通道形成鲜明对比，其寿命长达373 ps。更重要的是，BDP NPs中的超快NR通道（1.7 ps）消耗了相当一部分激发态种群（71%），这说明与分离的BDP染料相比，其光热效果要好得多。最后，BDP NPs显示了高效的光声成像（PAI）引导的活小鼠肿瘤光热治疗（PTT）。本研究对有机材料中的NR衰变有了更深入的认识，为类似分子结构开发更先进的有机材料提供了有价值的指导，不仅可以用于光热相关应用。
In-depth studies of nonradiative (NR) decay, seeking to maximize NR decay rate or manipulate other NR decay channels, are of greatest significance for improving the photothermal conversion efficiency (eta) of organic materials for phototheranostics; however, to date, relevant work remains scarce. Here, we present an insightful study of NR decay in BODIPY (BDP) dye, in an aggregated state, i.e., in BDP nanoparticles (BDP NPs), which show an efficient additional NR decay channel from the aggregation-stabilized intermolecular charge transfer (CT) state, resulting in exceptionally high eta (61%) for highly efficient phototheranostics in vivo. BDP NPs exhibit two ultrafast NR decay channels with ultrashort lifetimes of 1.7 and 50 ps, which is in stark contrast to the only S-1 -> S-0 NR channel with a long lifetime of 373 ps in the isolated BDP dye. More importantly, the ultrafast NR channel (1.7 ps) in BDP NPs depletes a substantial portion of the excited-state population (71%), which accounts for its much better photothermal effect as compared with the isolated BDP dye. Finally, BDP NPs display a highly efficient photoacoustic imaging (PAI) guided photothermal therapy (PTT) of tumors in live mice. This study presents a deeper fundamental understanding of NR decay in organic materials, setting a valuable guideline that may be widely applicable to similar molecular structure to develop more advanced organic materials not only for photothermal-related applications.