Facile and Scalable Preparation of Fluorescent Carbon Dots for Multifunctional Applications

• Published in: Engineering (Beijing, China) Vol. 3; no. 3; pp. 402 - 408
• Main Authors: Wang, Dan, Wang, Zhiyong, Zhan, Qiuqiang, Pu, Yuan, Wang, Jie-Xin, Foster, Neil R., Dai, Liming
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2017; Department of Chemical Engineering, Curtin University, Perth, WA 6845, Australia%Center of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Beijing Advanced Innovation Center for Soft Matter Science and Engineering& State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China; Center of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH 44106, USA%Beijing Advanced Innovation Center for Soft Matter Science and Engineering& State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China%SCNU-ZJU Joint Research Center of Photonics, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China%Beijing Advanced Innovation Center for Soft Matter Science and Engineering& State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China; Elsevier
• Subjects: Carbon dots; Fluorescence lifetime imaging; Patterning; Scalable; Two-photon; Fluorescence lifetime imaging; Patterning; Carbon dots; Scalable; Two-photon
• ISSN: 2095-8099
• DOI: 10.1016/J.ENG.2017.03.014

The synthesis of fluorescent nanomaterials has received considerable attention due to the great potential of these materials for a wide range of applications, from chemical sensing through bioimaging to optoelectron- ics. Herein, we report a facile and scalable approach to prepare fluorescent carbon dots （FCDs） via a one-pot reaction of citric acid with ethylenediamine at 150 ℃ under ambient air pressure. The resultant FCDs pos- sess an optical bandgap of 3.4 eV and exhibit strong excitation-wavelength-independent blue emission （λEm = 450 nm） under either one- or two-photon excitation. Owing to their low cytotoxicity and long fluorescence lifetime, these FCDs were successfully used as internalized fluorescent probes in human cancer cell lines （HeLa cells） for two-photon excited imaging of cells by fluorescence lifetime imaging microscopy with a high-contrast resolution. They were also homogenously mixed with commercial inks and used to draw fluo- rescent patterns on normal papers and on many other substrates （e.g., certain flexible plastic films, textiles, and clothes）. Thus, these nanomaterials are promising for use in solid-state fluorescent sensing, security labeling, and wearable optoelectronics.