Detection of trace Hg2+ via induced circular dichroism of DNA wrapped around single-walled carbon nanotubes.
The strongly induced circular dichroism (ICD) signals of DNA wrapped around single-walled carbon nanotubes (SWCNTs) are shown by the Synchrotron Radiation Facility. In solution, trace amounts of Hg ions have a strong affinity to bind the nucleic bases of DNA-SWCNTs via a pseudo-first-order kinetic reaction. The Hg binding to the bases of DNA results in partial DNA disassociation from the SWCNTs. Such disassociation of DNA from the SWCNTs will decrease the coupling effects of the transition dipole moments between DNA and SWCNTs, thus inducing the ICD signal of DNA-SWCNTs to decrease significantly. Herein, the ICD of DNA-SWCNTs is applied to detect the concentration of Hg ions at nM level.
Gao
Xueyun
X
Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Beijing 100049, PR China. gaoxy@ihep.ac.cn
Xing
Gengmei
G
Yang
Yanlian
Y
Shi
Xiaoli
X
Liu
Ru
R
Chu
Weiguo
W
Jing
Long
L
Zhao
Feng
F
Ye
Chang
C
Yuan
Hui
H
Fang
Xiaohong
X
Wang
Chen
C
Zhao
Yuliang
Y
D002413:Cations, Divalent / Q000737:chemistry; D002942:Circular Dichroism / Q000379:methods; D004247:DNA / Q000737:chemistry*; D008628:Mercury / Q000032:analysis / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D037742:Nanotubes, Carbon / Q000737:chemistry*
D002413:Cations, Divalent; D037742:Nanotubes, Carbon; D004247:DNA; D008628:Mercury