基于循环酶切放大和新型双信号策略的电化学DNA传感器研究

项目名称： 基于循环酶切放大和新型双信号策略的电化学DNA传感器研究

项目编号： No.21505121

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 吴靓

作者单位： 浙江师范大学

项目金额： 21万元

中文摘要： 双信号策略的出现为电化学DNA传感器的发展带来了新的方向。但是到目前为止，双信号DNA传感器的构筑都基于对DNA双链修饰不同的电信号物质，且双信号技术与其它信号放大策略联用的超灵敏检测方法尚未见报道。本项目通过对单链DNA的不同位置修饰不同的电化学标记物，实现单链DNA上的双信号变化，以此发展新型的双信号检测技术；再结合核酸外切酶 Ⅲ（exonuclease Ⅲ, Exo Ⅲ）对双链DNA的特异性识别、选择性降解及循环酶切对信号放大的作用，建立用于DNA链或汞离子检测的超灵敏电化学方法。先分别利用单一信号检测目标物；再进一步将双信号进行叠加或比值处理，获得多重放大型或比率型双信号电化学DNA传感器。本项目的研究不仅可以发展新型双信号检测技术，还将信号放大引入到双信号检测中，为双信号电化学DNA传感器的发展提供了新的思路，因此有重大的理论价值和应用前景。

中文关键词： 电化学DNA传感器；双信号策略；比率型电化学传感器；信号放大；核酸外切酶；Ⅲ

英文摘要： In the past years, the dual-signaling strategy has paved a new way for the development of the DNA-based electrochemical sensor. All the dual-signaling strategies before were based on the DNA duplex, which was modified with the different redox labels on both DNA strands. Moreover, there was no report about the combination of the dual-signaling strategy and other signal amplification methods in a DNA-based electrochemical sensor. In this project, different positions of single-stranded DNA (ssDNA) have been modified with different redox labels. The modified ssDNA can produce two different electrochemical signals, and a novel dual-signaling strategy has been developed. On the other hand, exonuclease Ⅲ (Exo Ⅲ) can catalyze the stepwise removal of mononucleotides from the 3'-hydroxyl terminus of DNA duplexes in the case of the substrate with a blunt or recessed 3' terminus. Take the advantages of the cyclic enzymatic amplification of Exo Ⅲ and the novel dual-signaling strategy, ultrasensitive bioassays for DNA strand or mercury ion are developed. The signal from each label is firstly used to detect target. Then, multiple-amplified or ratiometric DNA-based electrochemical sensors are obtained through the superposition or ratio of the dual signals. This project can not only develop a novel dual-signaling strategy based on ssDNA, but also provide a new approach about the combination of dual-signaling strategy and other signal amplification methods in electrochemical DNA-based biosensors. It has the great significance in theory and application.

英文关键词： DNA-based electrochemical sensor;dual-signaling strategy;ratiometric electrochemical sensor;signal amplification;exonuclease Ⅲ