title: Carbon nanotube-based label-free electrochemical biosensor for sensitive detection of miRNA-24.
abstract: The recent findings concerning the function of microRNAs (miRNAs) and the relationship between miRNA levels with specific disease highlight the need for miRNA detection. In this work, multi-walled carbon nanotubes (MWCNTs), having shown great potential for biosensors, were used to develop a simple, label-free, and sensitive electrochemical biosensor for detection of miRNA-24 by monitoring the oxidation signal of guanine. The synthetic DNA probes, being complementary with miRNA-24, were immobilized onto the surface of MWCNT-modified glass carbon electrodes by covalent cross-linking. The probes were hybridized with different concentrations of miRNA-24. The formed hybrids on the electrode surface were evaluated by differential pulse voltammetry. The change of guanine oxidation signal was observed as a result of the hybridization between the probes and miRNA-24. Control experiments using the non-complementary miRNA-29 were performed to evaluate the selectivity. Numerous factors affecting probe immobilization, target hybridization, and nonspecific binding events were optimized. Under the optimal conditions, the proposed miRNA-24 biosensor exhibits good sensitivity (4.963 μA cm(-2) decade(-1)), low detection limit (1 pM), and good selectivity and reproducibility. The biosensor also has acceptable recovery for miRNA-24 detection in complex miRNA sample.
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Fengye
authors.initials: F
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Peng
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. Electronic address: tanghao@hunnu.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Tang
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Tan
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Qingji
authors.initials: Q
authors.lastname: Xie
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China; State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China.
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006147:Guanine / Q000737:chemistry; D057230:Limit of Detection; D035683:MicroRNAs / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D035683:MicroRNAs; D037742:Nanotubes, Carbon; D006147:Guanine
keywords: Differential pulse voltammetry; Electrochemical biosensor; Label-free; Multi-walled carbon nanotube modified electrode; miRNA-24