Bifunctional colorimetric oligonucleotide probe based on a G-quadruplex DNAzyme molecular beacon.
A label-free bifunctional colorimetric oligonucleotide probe for DNA and protein detection has been developed on the basis of a novel catalytic molecular beacon consisting of two hairpin structures and a split G-quadruplex DNAzyme in the middle. The two loops of this molecular beacon consist of thrombin aptamer sequence and the complementary sequence of target DNA, which are utilized to sense single-stranded DNA and thrombin. The G-quadruplex DNAzyme can effectively catalyze the H(2)O(2)-mediated oxidation of 3,3',5,5'-tetramethylbenzidine sulfate to generate colorimetric signal. Upon addition of the target, the DNA or protein combines with one loop of the hairpin structures, and meanwhile drives the middle G-quadruplex DNAzyme to dissociate. This results in a decrease of catalytic activity, enabling the separate analysis of DNA and thrombin.
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
Libing
L
Zhang
Jinbo
J
Zhu
Tao
T
Li
Erkang
E
Wang
D001483:Base Sequence; D001560:Benzidines / Q000737:chemistry; D002384:Catalysis; D003124:Colorimetry; D021881:DNA, Catalytic / Q000737:chemistry* / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000032:analysis; D054856:G-Quadruplexes; D006861:Hydrogen Peroxide / Q000737:chemistry; D055029:Inverted Repeat Sequences; D015345:Oligonucleotide Probes / Q000737:chemistry*; D010084:Oxidation-Reduction; D013917:Thrombin / Q000032:analysis
D001560:Benzidines; D021881:DNA, Catalytic; D004277:DNA, Single-Stranded; D015345:Oligonucleotide Probes; C021758:3,3',5,5'-tetramethylbenzidine; D006861:Hydrogen Peroxide; D013917:Thrombin