• 文献标题:   Hydrothermal Preparation of Photoluminescent Graphene Quantum Dots Characterized Excitation-Independent Emission and its Application as a Bioimaging Reagent
  • 文献类型:   Article
  • 作  者:   ZHU XH, XIAO X, ZUO XX, LIANG Y, NAN JM
  • 作者关键词:  
  • 出版物名称:   PARTICLE PARTICLE SYSTEMS CHARACTERIZATION
  • ISSN:   0934-0866 EI 1521-4117
  • 通讯作者地址:   S China Normal Univ
  • 被引频次:   38
  • DOI:   10.1002/ppsc.201300375
  • 出版年:   2014

▎ 摘  要

Zero-dimensional photoluminescent (PL) graphene quantum dots (GQDs) that can be used as the cell-imaging reagent are prepared by a hydrothermal route using the graphene oxide (GO) as the carbon source. Under the optimized hydrothermal conditions, an initial hydrogen peroxide concentration of 0.5 mg mL(-1) at 180 degrees C for 120 min, the GO sheets can be cut into nanocrystals with lateral dimensions in the range of 1.5-5.5 nm and an average thickness of around 1.1 nm. The as-prepared GQDs exhibit an abundance of hydrophilic hydroxy and carboxyl groups and emit bright blue luminescence with up-conversion properties in a water solution at neutral pH. Most interestingly, they indicate excitation-independent emission characteristics, and the surface state is demonstrated to have a key role in the PL properties. The fluorescence quantum yield of the GQDs is tested to be around 6.99% using quinine sulfate as a standard. In addition, the as-prepared GQDs can enter into HeLa cells easily as a fluorescent imaging reagent without any further functionalization, indicating they are aqueous stability, biocompatibility, and promising for potential applications in biolabeling and solution state optoelectronics.