Ding Hui, Ji Yuan, Wei Ji-Shi, Gao Qing-Yu, Zhou Zi-Yuan, Xiong Huan-Ming
College of Chemical Engineering, China University of Mining and Technology, Xuzhou 221116, Jiangsu, P. R. China.
J Mater Chem B. 2017 Jul 14;5(26):5272-5277. doi: 10.1039/c7tb01130j. Epub 2017 Jun 20.
In this work, red-emitting carbon dots (R-CDs) with a high quantum yield (QY) of 28% in water were synthesized for the first time by heating an ethanol solution of pulp-free lemon juice. The obtained R-CDs were mono-dispersed with an average diameter of 4.6 nm, and exhibited excitation-independent emission at 631 nm. Meanwhile, these R-CDs featured low cytotoxicity and good photostability, which allow R-CDs to be employed as luminescent probes for in vitro/in vivo bioimaging. In addition, a detailed study on the physical properties and structural compositions of the sodium borohydride (NaBH) reduced R-CDs with orange emission suggested that surface states on the R-CD surfaces and nitrogen-derived structures in the R-CD cores synergistically caused their intense red luminescence. The low-cost and eco-friendly synthesis method and favorable optical properties of R-CDs make these carbon dots promising for further applications, such as bioimaging and light-emitting diodes.
在这项工作中，首次通过加热无果肉柠檬汁的乙醇溶液合成了在水中具有28%的高量子产率（QY）的红色发光碳点（R-CDs）。所获得的R-CDs呈单分散状态，平均直径为4.6 nm，并在631 nm处表现出与激发无关的发射。同时，这些R-CDs具有低细胞毒性和良好的光稳定性，这使得R-CDs能够用作体外/体内生物成像的发光探针。此外，对硼氢化钠（NaBH）还原的具有橙色发射的R-CDs的物理性质和结构组成进行的详细研究表明，R-CD表面的表面态和R-CD核心中的氮衍生结构协同导致了它们强烈的红色发光。R-CDs的低成本和环保合成方法以及良好的光学性质使得这些碳点在生物成像和发光二极管等进一步应用中具有前景。
