title: G-quadruplex based two-stage isothermal exponential amplification reaction for label-free DNA colorimetric detection.
abstract: A novel G-quadruplex based two-stage isothermal exponential amplification reaction (GQ-EXPAR) was developed for label-free DNA colorimetric detection in this work. The exponential amplified trigger DNA in the first stage can convert into G-quadruplex sequence EAD2 by a linear amplification circuit in the second stage. Created EAD2 can form G-quadruplex/hemin DNAzyme to act as a direct signal readout element. The GQ-EXPAR combines the exponential amplification of DNA sequence and the peroxidase-mimicking DNAzyme induced signal amplification, which achieves tandem dual-amplification. Taking advantages of isothermal incubation, this label-free homogeneous assay obviates the need of thermal cycling . As no complex synthesis or extra downstream operation is needed, the whole easy handling procedure can be finished in no more than 1h. This assay allows the sensing of the model DNA with the limit of detection to be 2.5pM. Moreover, it demonstrates good discrimination of mismatched sequences. The strategy has also been successfully implemented to sensitively detect Tay-Sachs genetic disorder mutant.
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry, Peking University, Beijing 100871, PR China.
authors: Ji
authors: J
authors: Nie
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry, Peking University, Beijing 100871, PR China.
authors: De-Wen
authors: DW
authors: Zhang
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry, Peking University, Beijing 100871, PR China.
authors: Cai
authors: C
authors: Tie
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry, Peking University, Beijing 100871, PR China. Electronic address: zhouyl@pku.edu.cn.
authors: Ying-Lin
authors: YL
authors: Zhou
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry, Peking University, Beijing 100871, PR China. Electronic address: zxx@pku.edu.cn.
authors: Xin-Xiang
authors: XX
authors: Zhang
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods; D003124:Colorimetry / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000378:metabolism; D021881:DNA, Catalytic / Q000378:metabolism; D054856:G-Quadruplexes; D057230:Limit of Detection; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*
chemical_list: D021881:DNA, Catalytic; D004247:DNA
keywords: Colorimetry; DNA detection; G-quadruplex; Isothermal exponential amplification; Label-free