Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7230816 | Biosensors and Bioelectronics | 2016 | 7 Pages |
Abstract
MicroRNAs play crucial role in post-transcriptional regulation for gene expression in animals, plants, and viruses. For the better understanding of microRNA and its functions, it is very important to develop effectively analytical method for microRNA detection. Herein, a novel electrochemical biosensor was fabricated for sensitive and selective detection of microRNA based on poly(U) polymerase mediated isothermal signal amplification, where poly(U) polymerase can catalyze the template independent addition of UMP from UTP to the 3' end of RNA. Using this activity, the target microRNA can be successfully labeled with biotin conjugated UMPs at its 3â²-end using biotin conjugated UTP (biotin-UTP) as donor. Then, the avidin conjugated alkaline phosphatase can be further captured to the 3â²-end of the target microRNA based on the specific interaction between biotin and avidin. Finally, under the catalytic activity of alkaline phosphatase, the substrate of p-nitrophenyl phosphate disodium salt hexahydrate can be hydrolyzed to produce 4-nitrophenol. According to the relationship between the electrochemical signal of p-nitrophenol and the concentration of microRNA-319a, the content of microRNA-319a can be detected. This signal amplification method is simple and sensitive. The developed method can detect as low as 1.7Â fM microRNA and produce precise and accurate linear dynamic range from 10 to 1000Â fM. The fabricated biosensor was further applied to detect the expression level change of microRNA-319a in rice seedlings after incubation with five kinds of different phytohormones.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Yunlei Zhou, Huanshun Yin, Jie Li, Bingchen Li, Xue Li, Shiyun Ai, Xiansheng Zhang,