Highly photoluminescent amino-functionalized graphene quantum dots used for sensing copper ions.
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.
Laboratory of Chemical Biology, Division of Biological Inorganic Chemistry, State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 (P. R. China), Fax: (+86) 431-85262656; University of Chinese Academy of Sciences, Beijing, 100039 (P.R. China).
Hanjun
H
Sun
Nan
N
Gao
Li
L
Wu
Jinsong
J
Ren
Weili
W
Wei
Xiaogang
X
Qu
D003300:Copper / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D049449:Luminescence; D045663:Quantum Dots / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D028561:Transition Elements / Q000737:chemistry*
D007477:Ions; D028561:Transition Elements; D006108:Graphite; D003300:Copper
amination; copper; fluorescence; graphene; quantum dots