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Highly Photoluminescent Amino‐Functionalized Graphene Quantum Dots Used for Sensing Copper Ions
Author(s) -
Sun Hanjun,
Gao Nan,
Wu Li,
Ren Jinsong,
Wei Weili,
Qu Xiaogang
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201302268
Subject(s) - graphene , quantum yield , fluorescence , quantum dot , photoluminescence , materials science , copper , metal ions in aqueous solution , chelation , ion , hydrothermal circulation , selectivity , surface modification , nanotechnology , ammonia , chemistry , chemical engineering , inorganic chemistry , organic chemistry , optoelectronics , catalysis , physics , quantum mechanics , engineering , metallurgy
Herein, we report a new kind of highly fluorescent probe for Cu 2+ sensing generated by hydrothermal treatment of graphene quantum dots (GQDs). After hydrothermal treatment in ammonia, the greenish‐yellow fluorescent GQDs (gGQDs) with a low quantum yield (QY, 2.5 %) are converted to amino‐functionalized GQDs (afGQDs) with a high QY (16.4 %). Due to the fact that Cu 2+ ions have a higher binding affinity and faster chelating kinetics with N and O on the surface of afGQDs than other transition‐metal ions, the selectivity of afGQDs for Cu 2+ is much higher than that of gGQDs. Furthermore, afGQDs are biocompatible and eco‐friendly, and the afGQDs with a positive charge can be easily taken up by cells, which makes it possible to sense Cu 2+ in living cells. The strategy presented here is simple in design, economical, and offers a “mix‐and‐detect” protocol without dye‐modified oligonucleotides or complex chemical modification.