Polaron engineering promotes NIR-II absorption of carbon quantum dots for bioimaging and cancer therapy

作者：Tesen Zhang, Bingzhe Wang, Quansheng Cheng, Qingcheng Wang, Qingqing Zhou, Lingyun Li, Songnan Qu, Handong Sun, Chu‐Xia Deng, Zikang Tang · 发表于：Science Advances · 年份：2024 · DOI：10.1126/sciadv.adn7896 · 被引用次数：43 · 研究领域：Carbon and Quantum Dots Applications、Luminescence and Fluorescent Materials、Quantum Dots Synthesis And Properties

Recent years have witnessed a surge of interest in tuning the optical properties of organic semiconductors for diverse applications. However, achieving control over the optical bandgap in the second near-infrared (NIR-II) window has remained a major challenge. To address this, here we report a polaron engineering strategy that introduces diverse defects into carbon quantum dots (CQDs). These defects induce lattice distortions resulting in the formation of polarons, which can absorb the near-field scattered light. Furthermore, the formed polarons in N-related vacancies can generate thermal energy through the coupling of lattice vibrations, while the portion associated with O-related defects can return to the ground state in the form of NIR-II fluorescence. On the basis of this optical absorption model, these CQDs have been successfully applied to NIR-II fluorescence imaging and photothermal therapy. This discovery could open a promising route for the polarons of organic semiconductor materials as NIR-II absorbers in nanomedical applications.