Cheng Fang-Fang, Zhang Jing-Jing, He Ting-Ting, Shi Jian-Jun, Abdel-Halim E S, Zhu Jun-Jie
State Key Lab of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P.R.China.
Analyst. 2014 Aug 21;139(16):3860-5. doi: 10.1039/c4an00777h.
The expression of microRNAs (miRNAs) is related to some cancer diseases. Recently, miRNAs have emerged as new candidate diagnostic and prognostic biomarkers for detecting a wide variety of cancers. Due to low levels, short sequences and high sequence homology among family members, the quantitative miRNA analysis is still a challenge. A novel electrochemical biosensor with triple signal amplification for the ultrasensitive detection of miRNA was developed based on phosphatase, redox-cycling amplification, a bimetallic Pd-Pt supported graphene functionalized screen-printed gold electrode, and two stem-loop structured DNAs as target capturers. The proposed biosensor is highly sensitive due to the enhanced electrochemical signal of Pd-Pt supported graphene and sufficiently selective to discriminate the target miRNA from homologous miRNAs in the presence of loop-stem structure probes with T4 DNA ligase. Therefore, this strategy provided a new and ultrasensitive platform for amplified detection and subsequent analysis of miRNA in biomedical research and clinical diagnosis.
微小RNA（miRNA）的表达与某些癌症疾病相关。最近，miRNA已成为用于检测多种癌症的新型候选诊断和预后生物标志物。由于其水平低、序列短且家族成员间序列同源性高，miRNA的定量分析仍然是一项挑战。基于磷酸酶、氧化还原循环扩增、双金属钯-铂负载的石墨烯功能化丝网印刷金电极以及两个茎环结构的DNA作为靶标捕获剂，开发了一种用于超灵敏检测miRNA的新型三重信号放大电化学生物传感器。所提出的生物传感器由于钯-铂负载石墨烯的电化学信号增强而具有高灵敏度，并且在存在T4 DNA连接酶的茎环结构探针的情况下，具有足够的选择性以区分靶标miRNA与同源miRNA。因此，该策略为生物医学研究和临床诊断中miRNA的扩增检测及后续分析提供了一个新的超灵敏平台。
