化学学报 ›› 2012, Vol. 70 ›› Issue (13): 1457-1463.DOI: 10.6023/A12040106 上一篇    下一篇

研究论文

基于纳米金膜和稳定Y型结构的DNA电化学传感器

董晓娅a,b, 赵伟伟a, 孙国宝a, 徐静娟a, 陈洪渊a   

  1. a 南京大学化学与化工学院 生命分析化学国家重点实验室 南京 210093;
    b 江苏大学农业工程研究院 镇江 212013
  • 收稿日期:2012-04-11 出版日期:2012-07-14 发布日期:2012-05-03
  • 通讯作者: 徐静娟 E-mail:xujj@nju.edu.cn
  • 基金资助:

    项目受国家重点基础研究发展计划(973计划, No. 2012CB932600)、国家自然科学基金(Nos. 21025522, 21135003)和国家自然科学基金委创新研究群体项目(No. 21121091)资助.

An Electrochemical DNA Biosensor Based on Gold Nanofilm and Stable Y Junction Structure

Dong Xiaoyaa,b, Zhao Weiweia, Sun Guobaoa, Xu Jingjuana, Chen Hongyuana   

  1. a State Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093;
    b Key Laboratory of Modern Agriculture Equipment and Technology, Jiangsu University, Zhenjiang 212013
  • Received:2012-04-11 Online:2012-07-14 Published:2012-05-03
  • Supported by:

    Project supported by 973 Program (No. 2012CB932600), the National Natural Science Foundation of China (Nos. 21025522, 21135003) and the National Natural Science Foundation of China for Creative Research Groups (No. 21121091).

利用纳米金膜(GNF)和稳定的Y 型DNA 成功构建了一种具有良好选择性和较低检测限的DNA 传感器. 首先将金电极快速氧化后还原制成GNF, 利用Au—S 键将捕获探针DNA (c-DNA)有效地固定到GNF 电极表面, 在目标物存在的情况下, 将其与标记有亚甲蓝(MB)的指示探针(r-DNA)杂交形成Y 型结构. 利用GNF 独特的纳米性质和形成的Y型DNA 结构特点, 使MB 接近GNF, 从而提高了电子传递速率, 以差分脉冲伏安法(DPV)实现DNA 特定序列的检测,检测线性范围为1.0×10-12~1.0×10-9 mol/L, 检测下限为2.4×10-13 mol/L. 与传统的传感器相比, 本方法提高了选择性, 减小了背景电流. 此外, 该传感器表现出良好的重现性和稳定性.

关键词: 电化学生物传感器, 金纳米膜, Y 结构DNA, 亚甲基蓝, DNA 传感器

On the basis of gold nanofilm (GNF) electrode and Y junction structure of DNA, a simple and facile single-step DNA sensing protocol with improved sensitivity and lower detection limit was successfully developed. The GNF was prepared via rapid electrooxidization of the gold surface followed by the chemical reduction of the produced gold oxide layer. The capture probe DNA (c-DNA) was firstly immobilized onto GNF electrodes via Au—S bonding, for the subsequent forming of Y junction structure with target DNA (t-DNA) and reporter probe DNA (r-DNA) labeled with methylene blue (MB). Harnessing the unique properties of GNF would allow the improved contact of MB with the electrode surface and hence boost the interfacial electron communication. Experimental results of differential pulse voltammetry (DPV) showed that the peak current of the prepared biosensor was linear with the target DNA concentration from 1.0×10-12 to 1.0×10-9 mol/L and the proposed strategy could detect the target DNA down to the level of 2.4×10-13 mol/L. Comparing with the traditional electrochemical sensors, the present protocol enabled the generation of electrochemical signal from scratch and possessed an improved selectivity against even a single base mismatch. Besides, this DNA sensor exhibited fairly good reproducibility, stability and reusability.

Key words: electrochemical biosensor, gold nanofilm, Y junction structure of DNA, methylene blue, DNA biosensor