Highly sensitive, selective, and rapid fluorescence Hg2+ sensor based on DNA duplexes of poly(dT) and graphene oxide.
Coupling T base with Hg(2+) to form stable T-Hg(2+)-T complexes represents a new direction in detection of Hg(2+). Here a graphene oxide (GO)-based fluorescence Hg(2+) analysis using DNA duplexes of poly(dT) that allows rapid, sensitive, and selective detection is first reported. The Hg(2+)-induced T(15)-(Hg(2+))(n)-T(15) duplexes make T(15) unable to hybridize with its complementary A(15) labelled with 6'-carboxyfluorescein (FAM-A(15)), which has low fluorescence in the presence of GO. On the contrary, when T(15) hybridizes with FAM-A(15) to form double-stranded DNA because of the absence of Hg(2+), the fluorescence largely remains in the presence of GO. A linear range from 10 nM to 2.0 μM (R(2) = 0.9963) and a detection limit of 0.5 nM for Hg(2+) were obtained under optimal experimental conditions. Other metal ions, such as Al(3+), Ag(+), Ca(2+), Ba(2+), Mg(2+), Zn(2+), Mn(2+), Co(2+), Pb(2+), Ni(2+), Cu(2+), Cd(2+), Cr(3+), Fe(2+), and Fe(3+), had no significant effect on Hg(2+) detection. Moreover, the sensing system was used for the determination of Hg(2+) in river water samples with satisfactory results.
Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Jian Rong
JR
Zhang
Wei Tao
WT
Huang
Wan Yi
WY
Xie
Ting
T
Wen
Hong Qun
HQ
Luo
Nian Bing
NB
Li
D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis* / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D010087:Oxides / Q000737:chemistry*; D011071:Poly T / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014867:Water / Q000737:chemistry
D004785:Environmental Pollutants; D010087:Oxides; D014867:Water; D011071:Poly T; D006108:Graphite; D004247:DNA; D008628:Mercury