氧化石墨烯增强荧光各向异性新策略在microRNA检测中的应用  

A new graphene oxide enhanced fluorescence anisotropy strategy for microRNA detection

作　　者：陶静 肖雪 李春宏 门晨 甄淑君[1,2] 

机构地区：[1]发光与实时分析化学教育部重点实验室 [2]西南大学化学化工学院,重庆400715

出　　处：《中国科学：化学》2018年第1期85-92,共8页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(编号:21305113);重庆市基础科学与前沿技术研究项目(编号:cstc2017jcyjBX0068);中央高校基本科研业务费(编号:XDJK2015B029)资助项目

摘　　要：microRNA(miRNA)是一类与癌症等重大疾病的发生密切相关的非编码小分子RNA.本文基于氧化石墨烯(GO)放大荧光各向异性(FA)原理,构建了GO/cDNA/Linker DNA/pDNA(DNA-GO)复合探针体系,结合靶物催化诱导信号循环放大策略,实现了miRNA-21的灵敏检测.在复合探针形成后,GO增加了荧光旋转体的体积和质量,Linker DNA上染料分子的荧光各向异性值增大.miRNA-21可通过"toehold"介导的链置换反应与Linker DNA杂交,使pDNA脱离Linker DNA.进一步加入Fuel DNA后,Fuel DNA与Linker DNA配对形成双链,从GO表面脱离,使Linker DNA上染料分子的荧光各向异性减小.被置换下来的miRNA-21进入下一循环,因此一个目标分子可以诱导形成多个Fuel DNA与Linker DNA的杂交双链,使荧光各向异性进一步减小.利用减小的荧光各向异性值实现了miRNA-21的灵敏检测.在本方法中,荧光各向异性减小值与miRNA-21浓度在10~330 nmol/L范围内呈线性关系,检测限为1.09 nmol/L.MicroRNAs （miRNA） are a class of small non-coding RNA molecules, whose abnormal expression or perturbation is associated with cancer and other diseases. Thus, identification of perturbed miRNAs using sensitive detection techniques is crucial. In view of this, we developed a novel graphene oxide （GO） amplified fluorescence anisotropy （FA） strategy for the detection ofmiRNA-21. In this method, a GO/capture DNA （cDNA）/Linker DNA/probe DNA （pDNA） （DNA-GO） composite probe was constructed, wherein target catalized singal cyclic amplification strategy was used to assist GO to amplify the FA signal. After the formation of DNA-GO composite probe, the FA of the fluorophore on Linker DNA was enhanced by GO because of the increased volume and mass. With the addition of miRNA-21, pDNA was released from Linker DNA through toehold-mediated strand exchange reaction. Fuel DNA then hybridized with Linker DNA to form a double-stranded DNA （dsDNA）, which was detached from the surface of GO, and FA of the fluorophore on Linker DNA was reduced. Additionally, miRNA-21 was released after the formation of dsDNA, which triggered the next cycle, resulting in further reduction of FA value. By monitoring the reduced FA values, miRNA-21 could be detected in the range of 10-330 nmol/L and the limit of detection （LOD） was 1.09 nmol/L.

关 键 词：氧化石墨烯 荧光各向异性 链置换反应 MICRORNA 

分 类 号：O657.3[理学—分析化学] R440[理学—化学]