PMID- 25375831
OWN - NLM
STAT- MEDLINE
DCOM- 20151013
LR  - 20141201
IS  - 1364-5528 (Electronic)
IS  - 0003-2654 (Linking)
VI  - 140
IP  - 1
DP  - 2015 Jan 7
TI  - Graphene oxide amplified fluorescence anisotropy for label-free detection of 
      potassium ion.
PG  - 353-7
LID - 10.1039/c4an01433b [doi]
AB  - Fluorescence anisotropy (FA) has attracted considerable attention, but it has 
      been rarely applied for the detection of small molecules and metal ions because 
      they are too small to induce evident FA changes. Although some mass amplifying 
      strategies have been developed, the recognition probes need to be covalently 
      modified with the fluorescent dyes, which is complex and expensive. To overcome 
      this limitation, a new simple, label-free and cost-effective method for the 
      sensitive detection of potassium ion (K(+)), by using graphene oxide (GO) as FA 
      enhancer, a G-rich single stranded DNA (ssDNA) as recognition probe and acridine 
      orange (AO) as FA reporting fluorophore, was established in this paper. In the 
      absence of K(+), both ssDNA and AO are adsorbed on the surface of GO, and the FA 
      of AO is enhanced greatly because the rotation of AO is coupled with the entire 
      formation. After the addition of K(+), the ssDNA self-associates into the 
      G-quadruplex structure. Then, AO can bind with the formed G-quadruplex strongly, 
      keeping away from the surface of GO, and the FA of AO decreases significantly 
      because of the relatively small size of the complex of AO and G-quadruplex. Thus 
      K(+) can be detected sensitively in the range of 10 muM-2 mM based on the 
      evidently decreased FA. This method is a further improvement of the previous 
      reported mass amplifying strategies because it does not require any covalent 
      labelling of the recognition probe, and it can be potentially applied for 
      detection of a variety of other targets.
FAU - Zhen, Shu Jun
AU  - Zhen SJ
AD  - Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest 
      University), Ministry of Education, College of Chemistry and Chemical 
      Engineering, Southwest University, 400715, Chongqing, P.R. China. 
      chengzhi@swu.edu.cn.
FAU - Yu, Yan
AU  - Yu Y
FAU - Li, Chun Mei
AU  - Li CM
FAU - Huang, Cheng Zhi
AU  - Huang CZ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Analyst
JT  - The Analyst
JID - 0372652
RN  - 0 (Ions)
RN  - 0 (Oxides)
RN  - 7782-42-5 (Graphite)
RN  - RWP5GA015D (Potassium)
SB  - IM
MH  - *Fluorescence Polarization
MH  - Graphite/*chemistry
MH  - Ions/analysis
MH  - Oxides/*chemistry
MH  - Potassium/*analysis
EDAT- 2014/11/07 06:00
MHDA- 2015/10/16 06:00
CRDT- 2014/11/07 06:00
PHST- 2014/11/07 06:00 [entrez]
PHST- 2014/11/07 06:00 [pubmed]
PHST- 2015/10/16 06:00 [medline]
AID - 10.1039/c4an01433b [doi]
PST - ppublish
SO  - Analyst. 2015 Jan 7;140(1):353-7. doi: 10.1039/c4an01433b.