Label-free electrochemical DNA biosensor based on a glassy carbon electrode modified with gold nanoparticles, polythionine, and graphene
Label-free electrochemical DNA biosensor based on a glassy carbon electrode modified with gold nanoparticles, polythionine, and graphene
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DOI：
10.1007/s00604-011-0742-9
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发表时间：
2012-02
影响因子：
5.7
通讯作者：
Yuzhong Zhang;Lei Huang
中科院分区：
文献类型：
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作者：
Yuzhong Zhang;Lei Huang
我们描述了一种灵敏的无标记电化学生物传感器的制作，用于测定序列特异性靶DNA。它基于用石墨烯、金纳米颗粒（Au-NPs）和聚噻吩（pThion）修饰的玻碳电极（GCE）。首先采用循环伏安法在石墨烯修饰的GCE表面电聚合噻吩。随后通过吸附将Au-NP沉积在pThion/石墨烯复合膜的表面上。利用扫描电子显微镜和电化学方法研究了组装过程。采用微分脉冲伏安法，通过测量pThion峰电流的变化来监测DNA的杂交。在最佳条件下，峰电流的下降与靶DNA浓度的对数在0.1 pM至10 nM范围内呈线性关系，检测限为35 fM（S/N为3）。该生物传感器具有良好的选择性、稳定性和重现性。图A制备了基于Au-NPs/pThion/graphene修饰电极的无标记DNA生物传感器。采用微分脉冲伏安法（DPV），通过测量pThion峰电流的变化来监测DNA杂交过程。
We describe the fabrication of a sensitive label-free electrochemical biosensor for the determination of sequence-specific target DNA. It is based on a glassy carbon electrode (GCE) modified with graphene, gold nanoparticles (Au-NPs), and polythionine (pThion). Thionine was firstly electropolymerized on the surface of the GCE that was modified with graphene by cyclic voltammetry. The Au-NPs were subsequently deposited on the surface of the pThion/graphene composite film by adsorption. Scanning electron microscopy and electrochemical methods were used to investigate the assembly process. Differential pulse voltammetry was employed to monitor the hybridization of DNA by measuring the changes in the peak current of pThion. Under optimal conditions, the decline of the peak current is linearly related to the logarithm of the concentration of the target DNA in the range from 0.1 pM to 10 nM, with a detection limit of 35 fM (at an S/N of 3). The biosensor exhibits good selectivity, acceptable stability and reproducibility.FigureA label-free DNA biosensor based on Au-NPs/pThion/graphene modified electrode has been fabricated. Differential pulse voltammetry (DPV) was employed to monitor DNA hybridization event by measurement of the peak current changes of pThion.