title: Ultrasensitive electrochemical detection of microRNA based on an arched probe mediated isothermal exponential amplification.
abstract: In this work, a simple and label-free electrochemical biosensor is developed for microRNA (miRNA) detection on the basis of an arched probe mediated isothermal exponential amplification reaction (EXPAR). The arched probe assembled on the electrode surface consists of two strands that are partially complementary to each other at both ends. The target can hybridize with the complementary sequence of the arched structure, leading to the cleavage of the probe. The strand fixed on the surface of the electrode self-assembles, in the presence of hemin, to G-quadruplex unit, yielding electrochemical signals. The other strand liberated into the solution triggers the EXPAR to recycle and regenerate targets. This method exhibits ultrahigh sensitivity toward miRNA with detection limits of 5.36 fM and a detection range of 3 orders of magnitude. The biosensor is capable of discriminating a single-nucleotide difference between concomitant miRNA and performs well in analyzing crude extractions from cancer cell lines.
authors: School of Pharmaceutical Sciences, Sun Yat-sen University , Guangzhou, Guangdong 510006, China.
authors: Yanyan
authors: Y
authors: Yu
authors: Zuanguang
authors: Z
authors: Chen
authors: Lijuan
authors: L
authors: Shi
authors: Fan
authors: F
authors: Yang
authors: Jianbin
authors: J
authors: Pan
authors: Beibei
authors: B
authors: Zhang
authors: Duanping
authors: D
authors: Sun
mesh_terms: D045744:Cell Line, Tumor; D015342:DNA Probes / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D035683:MicroRNAs / Q000032:analysis*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods
chemical_list: D015342:DNA Probes; D035683:MicroRNAs; D006427:Hemin