文档介绍：基于纳米金和核酸外切酶双重信号放大 技术的非标型电化学DNA传感器
孔荣梅，宋志灵，张晓兵
(湖南大学化学化工学院，化学生物传感与计量学国家重点实验室，长沙410082) 摘要：本文提出了一种基于核酸外切酶和纳米金功能化DNA双重信号放大技术的非标型电化 学DNA传感器。该传感器首先在均相中进行发夹型探针和目标DNA之间的杂交及酶切反应, 避免了电极表面进行酶切所遇到的酶效率降低等缺点，而且该发夹型探针能够提供较好的碱 基错配识别能力；然后将酶切产物序列与电极表面的发夹型捕获探针杂交，进一步提高了碱 基错配识别能力；最后利用纳米金功能化的报告探针进行信号放大，以亚***蓝为电活性物 质，实现了对目标DNA的高灵敏和高特异性电化学检测， pM。该方法操作简 便、灵敏度高、特异性好，可简易再生，能够多次稳定使用。
关键词：分析化学；信号放大；电化学传感器；DNA检测；纳米金；核酸外切酶 中图分类号：
A Label-Free Electrochemical Biosensor for Highly Sensitive
Detection of DNA via Gold Nanoparticle and Enzymatic
Dual Signal Amplifications
KONG Rongmei, SONG Zhiling, ZHANG Xiaobing
(State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, ChangSha 410082)
Abstract: This work reports the development of a label-free electrochemical DNA biosensor based on gold nanoparticle and enzymatic dual signal amplifications. In the design, take advantage of the improved mismatch distinguishing ability of MB, the hairpin probe first hybridizes with target DNA to trigger the enzymatic recycling reaction in the presence of exonuclease III, which could avoid the low enzymatic reaction efficiency, effectively. Then, the cleaved sequences hybridize with the hairpin capture probe, which can further improve the mismatch distinguishing ability of the sensing system. Finally, the gold nanoparticles functionalized re