title: Carbon nanotube-polyamidoamine dendrimer hybrid-modified electrodes for highly sensitive electrochemical detection of microRNA24.
abstract: A simple and ultrasensitive microRNA (miRNA) electrochemical biosensor employing multiwalled carbon nanotube (MWCNT)-polyamidoamine (PAMAM) dendrimer and methylene blue (MB) redox indicator is reported in this work. The assay utilizes a glass carbon (GC) electrode modified with MWCNT-PAMAM, on which the oligonucleotide capture probes are immobilized. The electrochemical detection of miRNAs is completed by measuring the reduction signal change of MB before and after the probe hybridization with target miRNA (miRNA24 is used as a model case). The MWCNT-PAMAM/GC electrode shows greatly enhanced signal to MB reduction in contrast to bare GC electrode. The functionalization of MWCNT with PAMAM maintains the electrochemical property of MWCNT to MB reduction but minimizes the undesired adsorption of MB on the MWCNT surface. The effect of experimental variables on the miRNA detection is investigated and optimized. A detection limit of 0.5 fM and a linear peak current density-concentration relationship up to 100 nM are obtained following 60 min hybridization. The proposed assay is successfully used to detect miRNA24 in total RNA sample extracted from HeLa cells.
authors: †Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, People's Republic of China.
authors: Fengye
authors: F
authors: Li
authors: †Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, People's Republic of China.
authors: Jing
authors: J
authors: Peng
authors: †Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, People's Republic of China.
authors: Qiong
authors: Q
authors: Zheng
authors: †Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, People's Republic of China.
authors: Xiang
authors: X
authors: Guo
authors: †Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, People's Republic of China.
authors: Hao
authors: H
authors: Tang
authors: †Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, People's Republic of China.|§State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, People's Republic of China.
authors: Shouzhuo
authors: S
authors: Yao
mesh_terms: D050091:Dendrimers / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D006367:HeLa Cells; D006801:Humans; D035683:MicroRNAs / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*
chemical_list: D050091:Dendrimers; D035683:MicroRNAs; D037742:Nanotubes, Carbon; C531249:Poly(amidoamine); D011073:Polyamines