title: Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging.
abstract: Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM(+) on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 ± 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection.
authors.affiliation: College of Materials Science and Engineering; Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory; Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province; Qingdao University, Ningxia Road 308, Qingdao 266071, China. yhxu@qdu.edu.cn jliu@qdu.edu.cn.
authors.forename: Fushuang
authors.initials: F
authors.lastname: Niu
authors.forename: Yuanhong
authors.initials: Y
authors.lastname: Xu
authors.forename: Mengli
authors.initials: M
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.forename: Pengran
authors.initials: P
authors.lastname: Guo
authors.forename: Jingquan
authors.initials: J
authors.lastname: Liu
mesh_terms: D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006367:HeLa Cells; D006801:Humans; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D007477:Ions; D008027:Light; D049449:Luminescence; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010777:Photochemistry; D056951:Photoelectron Spectroscopy; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: C412621:1-butyl-3-methylimidazolium hexafluorophosphate; D007093:Imidazoles; D052578:Ionic Liquids; D007477:Ions; D037742:Nanotubes, Carbon; D002244:Carbon