Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (13): 1457-1463.DOI: 10.6023/A12040106 Previous Articles     Next Articles



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
  • 投稿日期:2012-04-11 发布日期:2012-05-03
  • 通讯作者: 徐静娟
  • 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 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).

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