Photoluminescence mechanism and applications of Zn-doped carbon dots. Issue 31 (11th May 2018)

• Record Type: Journal Article
• Authors: 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
• Is Part Of: RSC advances. Volume 8:Issue 31(2018)
• Page Start: 17254
• Page End: 17262
• Publication Date: 2018-05-11
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra02756k
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Zinc ions, acting as a surface passivating agent, prevented the aggregation of graphene π–π stacking and increased the quantum yield of Zn-carbon dots. Abstract : 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 2+ 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 in vivo sensing and future phototherapy applications.