title: Ultrasensitive electrochemical detection of microRNA-21 combining layered nanostructure of oxidized single-walled carbon nanotubes and nanodiamonds by hybridization chain reaction.
abstract: Measurement of microRNA (miRNA) levels in body fluids is a crucial tool for the early diagnosis and prognosis of cancers. In this study, we developed an electrochemical assay to detect miRNA-21 by fabricating the electrode with layer-by-layer assembly of oxidized single-walled carbon nanotubes and nanodiamonds. Tetrahedron-structured probes with free-standing probe on the top served as receptors to hybridize with target miRNA directly. The probes were immobilized on the deposited gold nanoparticles through a well-established strong Au-S bond. The electrochemical signal was mainly derived from an ultrasensitive pattern by combining hybridization chain reaction with DNA-functionalized AuNPs, which provided DNAzyme to catalyze H2O2 reduction. Differential pulse voltammetry was applied to record the electrochemical signals, which was increased linearly with the target miRNA-21, and the linear detection range was 10 fM to 1.0 nM. The limit of detection reached 1.95 fM (S/N=3), and the proposed biosensor exhibited good reproducibility and stability, as well as high sensitivity. Hence, this biosensor has a promising potential in clinical application.
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Lingzhi
authors.initials: L
authors.lastname: Liu
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Song
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: guomingxie@cqmu.edu.cn.
authors.forename: Guoming
authors.initials: G
authors.lastname: Xie
mesh_terms: D003217:Conductometry / Q000379:methods*; D035683:MicroRNAs / Q000032:analysis* / Q000235:genetics*; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D058612:Nanodiamonds / Q000737:chemistry* / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization / Q000379:methods*; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D058612:Nanodiamonds; D037742:Nanotubes, Carbon
keywords: Hybridization chain reaction; MicroRNA-21; Nanodiamonds; Oxidized single-walled carbon nanotubes; Tetrahedron-structured probes