State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, Jilin 130012, China; Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
Faculty of Health Science, University of Macau, Taipa 999078, Macau.
Biomaterials. 2017 Nov;144:42-52. doi: 10.1016/j.biomaterials.2017.08.007. Epub 2017 Aug 12.
Semiconducting polymers with specific absorption are useful in various applications, including organic optoelectronics, optical imaging, and nanomedicine. However, the optical absorption of a semiconducting polymer with a determined structure is hardly tunable when compared with that of inorganic semiconductors. In this work, we show that the optical absorption of polymer nanoparticles from one conjugated backbone can be effectively tuned through judicious design of the particle morphology and the persistence length of polymers. Highly absorbing near-infrared (NIR) polymers based on diketopyrrolopyrrole-dithiophene (DPP-DT) are synthesized to have different molecular weights (MWs). The DPP-DT polymer with a large molecular weight and high persistence length exhibited remarkably high optical absorption with a peak mass extinction coefficient of 81.7 L g cm, which is one of the highest value among various photothermal agents reported to date. Particularly, the polymer nanoparticles with different sizes exhibit broadly tunable NIR absorption peaks from 630 to 811 nm. The PEGylated small polymer dots (Pdots) show good NIR light-harvesting efficiency and high non-radiative decay rates, resulting in a relatively high photothermal conversion efficiency in excess of 50%. Thus, this Pdot-based platform can serve as promising photothermal agents and photoacoustic probes for cancer theranostics.
具有特定吸收能力的半导体聚合物在各种应用中非常有用，包括有机光电、光学成像和纳米医学。然而，与无机半导体相比，具有确定结构的半导体聚合物的光学吸收很难进行调节。在这项工作中，我们表明，通过合理设计颗粒形态和聚合物的持久性长度，可以有效地调节来自一个共轭主链的聚合物纳米颗粒的光学吸收。我们合成了基于二酮吡咯并吡咯二噻吩 (DPP-DT) 的具有不同分子量 (MW) 的高吸收近红外 (NIR) 聚合物。具有大分子量和高持久性长度的 DPP-DT 聚合物表现出显著的高光学吸收，其峰值质量消光系数为 81.7 L g cm，这是迄今为止报道的各种光热剂中最高值之一。特别是，具有不同尺寸的聚合物纳米颗粒表现出从 630 到 811nm 的广泛可调的近红外吸收峰。聚乙二醇化的小聚合物点 (Pdots) 表现出良好的近红外光捕获效率和高非辐射衰减率，导致光热转换效率超过 50%。因此，基于这种 Pdot 的平台可以作为有前途的光热治疗剂和光声探针用于癌症治疗。
