title: Nitrogen and sulfur co-doped carbon dots for highly selective and sensitive detection of Hg (II) ions.
abstract: Nitrogen and sulfur co-doped carbon dots (N,S/C-dots) with high fluorescence quantum yields (FLQY, 25%) was successfully synthesized by a one-step microwave-assisted method. In comparison with nitrogen doped C-dots (N/C-dots) prepared using the same method, the resulting N,S/C-dots featured small particle size, uniform surface state, insensitive FL properties to excitation wavelengths and environmental conditions, negligible cytotoxicity and excellent biocompatibility. Simultaneous doping of N and S effectively promoted electron-transfer and coordination interaction between N,S/C-dots and Hg(2+). Thus, when used as fluorescence probe for Hg(2+) label-free detection, the resulting N,S/C-dots showed good detection sensitivity and ion selectivity. The limit of detection was 2 μM; among 15 metal ions investigated, only Fe(3+) showed interference to the Hg(2+) detection. Fortunately, this interference could be effectively shielded using a chelating agent sodium hexametaphoshpate. The applicability of N,S/C-dots as fluorescence probe for Hg(2+) detection in lake water and tap water was demonstrated. Finally, based on its favorable features of negligible cytotoxicity and excellent biocompatibility, the N,S/C-dots were successfully applied to probe Hg(2+) in living cells, which broaden its application in biological system.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Life Science, Jilin University, Changchun, Jilin 130012, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China. Electronic address: youty@ciac.jl.cn.
authors.forename: Tianyan
authors.initials: T
authors.lastname: You
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D002413:Cations, Divalent / Q000032:analysis; D002460:Cell Line; D060766:Drinking Water / Q000032:analysis; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D060106:Lakes / Q000032:analysis; D008628:Mercury / Q000032:analysis*; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D061848:Optical Imaging / Q000379:methods; D013050:Spectrometry, Fluorescence / Q000379:methods; D013455:Sulfur / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D060766:Drinking Water; D005456:Fluorescent Dyes; D013455:Sulfur; D002244:Carbon; D008628:Mercury; D009584:Nitrogen
keywords: Carbon dots; Hg(2+) Ions detection; Nitrogen and sulfur co-doped