College of Electronic and Optical Engineering & College of Flexible Electronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
Colloids Surf B Biointerfaces. 2022 Dec;220:112869. doi: 10.1016/j.colsurfb.2022.112869. Epub 2022 Sep 22.
Recently, red emissive carbon dots (R-CDs) have drawn widespread attention on account of their desirable fluorescence properties and good biocompatibility. Despite great efforts, facile synthesis of R-CDs for cellular imaging remains challenging and the fluorescence mechanism of R-CDs is still elusive. Herein, p-phenylenediamine-derived R-CDs with excitation-independency were successfully obtained through a facile solvothermal approach together with proportional precipitation. The fluorescent solvatochromism of R-CDs is realized, while high polarity leads to higher degree of dipole interaction between R-CDs and different solvents, favoring for emissive red-shift. Furthermore, density functional theory is adopted to explore the optical and electronic characteristics of some polycyclic aromatic molecules. Among different configurations, pyridine nitrogen and carbonyl bonds could relatively increase the charge density and significantly narrow the band gap, which can provide a crucial theoretical basis for the precise preparation of R-CDs. Moreover, R-CDs possess favorable cellular imaging ability, which indicates their potential for a promising candidate as fluorescence probes in bioimaging.
近年来，红色发射碳点（R-CDs）因其理想的荧光性质和良好的生物相容性而引起了广泛关注。尽管已经做出了很大的努力，但用于细胞成像的简便合成 R-CDs 仍然具有挑战性，并且 R-CDs 的荧光机制仍然难以捉摸。在此，通过简便的溶剂热法结合比例沉淀，成功获得了具有激发独立性的对苯二胺衍生的 R-CDs。实现了 R-CDs 的荧光溶剂化变色，而高极性导致 R-CDs 与不同溶剂之间的偶极相互作用程度更高，有利于发射红移。此外，采用密度泛函理论来探究一些多环芳烃分子的光学和电子特性。在不同的构型中，吡啶氮和羰基键可以相对增加电荷密度，并显著缩小带隙，这为 R-CDs 的精确制备提供了重要的理论基础。此外，R-CDs 具有良好的细胞成像能力，这表明它们有望成为生物成像中荧光探针的有前途的候选物。
