title: An isothermal electrochemical biosensor for the sensitive detection of microRNA based on a catalytic hairpin assembly and supersandwich amplification.
abstract: A novel isothermal electrochemical biosensor was proposed for the sensitive detection of microRNA (miRNA) based on the ingenious combination of the target-catalyzed hairpin assembly (CHA) and supersandwich amplification strategies. Since miRNA-221 has been reported to be overexpressed in cancers and has been a potentially useful biomarker for the diagnosis of the related diseases, miRNA-221 was chosen as a model target miRNA. The target miRNA-221 triggered a toehold strand displacement assembly of the two hairpin substrates, which led to the cyclicality of the target miRNA and the CHA products. Subsequently, the CHA products hybridized with a capture probe on the electrode and the exposed stem of the CHA products was further used to propagate the supersandwich. After this, the signal probe was modified with horseradish peroxidase (HRP) to form a supersandwich multiplex HRP-DNA label, which could achieve an amplified electrochemical signal. Using the isothermal dual signal amplification strategies, miRNA-221 as low as 0.6 pM (3σ) could be detected. In addition, this biosensor showed high selectivity and could discriminate miRNA-221 from the homologous miRNAs. Note that human miRNA from cancer cells could also be detected and the results were in excellent agreement with those obtained using qRT-PCR. Given that the biosensor avoided the introduction of nanoparticles, the limitation of using the nanoparticles was overcome. The proposed biosensor has great potential for broad applications in the field of clinical analysis.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Kemin
authors.identifier: 0000-0002-7337-0999
authors.initials: K
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Wenyan
authors.initials: W
authors.lastname: Nie
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha, 410082 China. wwqq99@hnu.edu.cn kmwang@hnu.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D001560:Benzidines / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D045744:Cell Line, Tumor; D015342:DNA Probes / Q000235:genetics; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D057230:Limit of Detection; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques / Q000295:instrumentation* / Q000379:methods; D009693:Nucleic Acid Hybridization; D015347:RNA Probes / Q000235:genetics; D013696:Temperature
chemical_list: D001560:Benzidines; D015342:DNA Probes; D035683:MicroRNAs; D015347:RNA Probes; C021758:3,3',5,5'-tetramethylbenzidine; D006046:Gold; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase