Simultaneous detection of multiple DNA targets based on encoding metal ions.
We present a novel strategy for simultaneous electrochemical detection of multiple DNA targets based on the use of different encoding metal ions as tags. The principle of this scheme is that metal ions bound to metallothionein (MT) molecules can be released down after hybridization with DNA targets and then be detected by stripping voltammetry. The novel detection probes, ssDNA/MT conjugates, covered with different metal ions were synthesized for the first time, then three encoding metal ions (Zn(2+), Cd(2+), and Pb(2+)) were used to differentiate the signals of three virus DNA due to their well-defined anodic stripping peaks at -1.13 V (Zn), -0.78 V (Cd), and -0.52 V (Pb) at BiFE, respectively. The anodic peak currents increased linearly with the concentrations of DNA targets in the range from 0.1 nM to 10nM with a detection limit of 33 pM. In addition, the one-base mismatched target was effectively discriminated from the complementary target. The described results demonstrated that this method possesses high sensitivity and selectivity for multi-target DNA assay and has great potential in applications for detection of even more targets in biological assays, particularly immunoassays.
Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, No. 967 Anning East Road, Lanzhou, Gansu 730070, China.
Lichun
L
Zheng
Xiaoyan
X
Li
Panpan
P
Liu
Guofan
G
Wu
Xiaoquan
X
Lu
Xiuhui
X
Liu
D015374:Biosensing Techniques / Q000379:methods*; D002104:Cadmium / Q000737:chemistry; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D055664:Electrochemical Techniques; D007118:Immunoassay; D007477:Ions / Q000737:chemistry*; D007854:Lead / Q000737:chemistry; D057230:Limit of Detection; D008668:Metallothionein / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D015032:Zinc / Q000737:chemistry
D007477:Ions; D002104:Cadmium; D007854:Lead; D004247:DNA; D008668:Metallothionein; D015032:Zinc
DNA biosensors; Metal ions; Metallothioneins; Multiplex analysis; Stripping voltammetry