Xu Quan, Cai Wei, Zhang Miaoran, Su Rigu, Ye Yingchun, Li Yeqing, Zhang Lipeng, Guo Yongjian, Yu Zhiqiang, Li Siyu, Lin Xun, Chen Yusheng, Luo Yan, Street Jason, Xu Meng
State Key Laboratory of Heavy Oil Processing Beijing 102249 China
College of Energy, Beijing University of Chemical Technology Beijing 100029 China
RSC Adv. 2018 May 11;8(31):17254-17262. doi: 10.1039/c8ra02756k. eCollection 2018 May 9.
Heteroatom-doped carbon dots (CDs) with excellent optical characteristics and negligible toxicity have emerged in many applications including bioimaging, biosensing, photocatalysis, and photothermal therapy. The metal-doping of CDs using various heteroatoms results in an enhancement of the photophysics but also imparts them with multifunctionality. However, unlike nonmetal doping, typical metal doping results in low fluorescence quantum yields (QYs), and an unclear photoluminescence mechanism. In this contribution, we detail results concerning zinc doped CDs (Zn-CDs) with QYs of up to 35%. The zinc ion charges serve as a surface passivating agent and prevent the aggregation of graphene π-π stacking, leading to an increase in the QY of the Zn-CDs. Structural and chemical investigations using spectroscopic and first principle simulations further revealed the effects of zinc doping on the CDs. The robust Zn-CDs were used for the ultra-trace detection of Hg with a detection limit of 0.1 μM, and a quench mechanism was proposed. The unique optical properties of the Zn-CDs have promise for use in applications such as sensing and future phototherapy applications.
具有优异光学特性且毒性可忽略不计的杂原子掺杂碳点（CDs）已出现在包括生物成像、生物传感、光催化和光热疗法在内的许多应用中。使用各种杂原子对CDs进行金属掺杂不仅会增强其光物理性质，还赋予它们多功能性。然而，与非金属掺杂不同，典型的金属掺杂会导致荧光量子产率（QYs）较低，且光致发光机制不明确。在本论文中，我们详细介绍了锌掺杂碳点（Zn-CDs）的相关结果，其量子产率高达35%。锌离子电荷作为表面钝化剂，可防止石墨烯π-π堆积的聚集，从而导致Zn-CDs的量子产率增加。使用光谱和第一性原理模拟进行的结构和化学研究进一步揭示了锌掺杂对碳点的影响。坚固的Zn-CDs用于汞的超痕量检测，检测限为0.1 μM，并提出了淬灭机制。Zn-CDs独特的光学性质有望用于传感等应用以及未来的光疗应用。
