title: Hairpin assembly-triggered cyclic activation of a DNA machine for label-free and ultrasensitive chemiluminescence detection of DNA.
abstract: DNA plays important regulatory roles in many life activities. Here, we have developed a novel label-free, ultrasensitive and specific chemiluminescence (CL) assay protocol for DNA detection based on hairpin assembly-triggered cyclic activation of a DNA machine. The system involves two hairpin structures, H1 and H2. Firstly, a target DNA binds with and opens the hairpin structure of H1. Then, H2 hybridizes with H1 and displaces the target DNA, which is used to trigger another new hybridization cycle between H1 and H2, leading to the generation of numerous H1-H2 complexes. The generated H1-H2 complexes are further activated with the help of polymerase and nicking enzyme, continuously yielding a large amount of G-riched DNA fragments. The G-riched DNA fragment products interact with hemin to form the activated HRP-mimicking DNAzymes that can catalyze the oxidation of luminol by H2O2 to produce strong CL signal resulting in an amplified sensing process. Our newly proposed homogeneous assay enables the quantitative measurement of p53 DNA (as a model) with a detection limit of 0.85 fM, which is at least 5 orders of magnitude lower than that of traditional unamplified homogeneous optical approaches. Moreover, this assay exhibits high discrimination ability even against a single base mismatch. In addition, this strategy is also capable of detecting p53 DNA in complex biological samples. The proposed sensing approach might hold a great promise for further applications in biomedical research and early clinical diagnosis.
authors: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors: Jia
authors: J
authors: Chen
authors: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: hdqiu@licp.cas.cn.
authors: Hongdeng
authors: H
authors: Qiu
authors: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors: Mingliang
authors: M
authors: Zhang
authors: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors: Tongnian
authors: T
authors: Gu
authors: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors: Shijun
authors: S
authors: Shao
authors: Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), College of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, China.
authors: Yong
authors: Y
authors: Huang
authors: Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), College of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, China.
authors: Shulin
authors: S
authors: Zhao
mesh_terms: D015374:Biosensing Techniques; D003124:Colorimetry; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D021881:DNA, Catalytic / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D055029:Inverted Repeat Sequences; D049449:Luminescence; D008163:Luminescent Measurements
chemical_list: D021881:DNA, Catalytic; D004247:DNA; D006861:Hydrogen Peroxide
keywords: Chemiluminescence; DNA machine; Hairpin assembly; Label-free; P53 DNA