State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Adv Mater. 2020 Apr;32(17):e1906641. doi: 10.1002/adma.201906641. Epub 2020 Mar 19.
Development of high-performance carbon dots (CDs) with emission wavelength longer than 660 nm (deep red emission) is critical in deep-tissue bioimaging, yet it is still a major challenge to obtain CDs with both narrow full width at half maximum (FWHM) and high deep red/near-infrared emission yield. Here, deep red emissive carbonized polymer dots (CPDs) with unprecedented FWHM of 20 nm are synthesized. The purified CPDs in dimethyl sulfoxide (DMSO) solution possess quantum yield (QY) as high as 59% under 413 nm excitation, as well as recorded QY of 31% under 660 nm excitation in the deep red fluorescent window. Detailed characterizations identify that CPDs have unique polymer characteristics, consisting of carbon cores and the shells of polymer chains, and π conjugated system formed with N heterocycles and aromatic rings governs the single photoluminescence (PL) center, which is responsible for high QY in deep red emissive CPDs with narrow FWHM. The CPDs exhibit strong absorption and emission in the deep red light region, low toxicity, and good biocompatibility, making them an efficient probe for both one-photon and two-photon bioimaging. CPDs are rapidly excreted via the kidney system and hepatobiliary system.
开发具有超过 660nm（深红色发射）发射波长的高性能碳点（CDs）对于深层组织生物成像至关重要，但获得具有窄全宽半最大值（FWHM）和高深红色/近红外发射产率的 CDs 仍然是一个主要挑战。在这里，合成了具有前所未有的 20nm 全宽半最大值的深红色发射碳化聚合物点（CPDs）。在二甲基亚砜（DMSO）溶液中的纯化 CPDs 在 413nm 激发下具有高达 59%的量子产率（QY），在深红色荧光窗口下在 660nm 激发下记录的 QY 为 31%。详细的特性分析表明，CPDs 具有独特的聚合物特性，由碳核和聚合物链的壳组成，由 N 杂环和芳环形成的π共轭体系控制单光致发光（PL）中心，这是深红色发射窄 FWHM 的 CPDs 具有高 QY 的原因。CPDs 在深红色光区域具有强吸收和发射、低毒性和良好的生物相容性，使其成为单光子和双光子生物成像的有效探针。CPDs 通过肾脏系统和肝胆系统迅速排泄。
