Carbon nanotube-based label-free electrochemical biosensor for sensitive detection of miRNA-24

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• 作者：Fengye Li ; Jing Peng ; Jingjing Wang ; Hao Tang ; Liang Tan ; Qingji Xie ; Shouzhuo Yao
• 关键词：Multi-walled carbon nanotube modified electrode ; miRNA-24 ; Label-free ; Differential pulse voltammetry ; Electrochemical biosensor
• 刊名：Biosensors and Bioelectronics
• 出版年：15 April, 2014
• 年：2014
• 卷：54
• 期：Complete
• 页码：158-164
• 全文大小：837 K

文摘

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 渭A cm^鈭? decade^鈭?), low detection limit (1 pM), and good selectivity and reproducibility. The biosensor also has acceptable recovery for miRNA-24 detection in complex miRNA sample.