基于纳米金膜和稳定Y型结构的DNA电化学传感器  

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

作　　者：董晓娅[1,2] 赵伟伟[1] 孙国宝[1] 徐静娟[1] 陈洪渊[1] 

机构地区：[1]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 [2]江苏大学农业工程研究院,镇江212013

出　　处：《化学学报》2012年第13期1457-1463,共7页Acta Chimica Sinica

基　　金：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);国家自然科学基金委创新研究群体项目(No.21121091)资助~~

摘　　要：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1.0×10-12～1.0×10-9mol/L,检测下限为2.4×10-13mol/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.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 pre- pared 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 re- producibility, stability and reusability.

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 

分 类 号：TP212.2[自动化与计算机技术—检测技术与自动化装置]