A label-free electrochemical DNA biosensor based on thionine functionalized reduced graphene oxide
A label-free electrochemical DNA biosensor based on thionine functionalized reduced graphene oxide
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DOI：
10.1016/j.carbon.2017.12.060
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发表时间：
2018-04
期刊：
影响因子：
10.9
通讯作者：
Yongkang Ye;Jingqi Xie;Y. Ye;Xiaodong Cao;Haisong Zheng;Xuan Xu;Zhang Qiang
中科院分区：
文献类型：
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作者：
Yongkang Ye;Jingqi Xie;Y. Ye;Xiaodong Cao;Haisong Zheng;Xuan Xu;Zhang Qiang
本文在玻璃碳电极（GCE）上设计了一个转导接口，构建了无标记DNA生物传感器。该界面由捕获DNA序列（CP）、金纳米颗粒（AuNPs）和硫氨酸功能化还原氧化石墨烯（Thi-rGO）组成。由于Thi-氧化石墨烯纳米复合材料中优异的电化学活性，直接由硫氨酸的氧化还原反应诱导信号转导。然而，氧化还原反应将被随后固定在GCE表面的生物分子所阻碍。因此，可以通过监测CP与tDNA杂交前后Thi的伏安响应电流来实现靶序列（tDNA）的确定。在最优条件下,峰电流与浓度的对数线性下降的范围从1.0 tDNA×10−17 1.0 × 10−12米的检测极限4.28 × 10−19米 (S / N = 3)。该DNA生物传感器具有选择性好、稳定性好、制备重复性好等优点。将该传感器应用于实际生物样品的tDNA检测，回收率为95.61 ~ 101.8%。
In this paper, a transducing interface was designed on a glassy carbon electrode (GCE) to construct a label-free DNA biosensor. The interface was consisted of capture DNA sequence (CP), gold nanoparticles (AuNPs), and thionine functionalized reduced graphene oxide (Thi-rGO). The signal transduction induced directly from redox reaction of thionine because of the excellent electrochemical activity of Thi in the Thi-rGO nanocomposite. However, the redox reaction will be hindered by the biomolecules that immobilized subsequently onto the surface of GCE. Therefore, the determination of target sequence (tDNA) can be realized by monitoring the voltammetric response current of Thi before and after the hybridization between CP and tDNA. Under the optimal conditions, the peak current decreased linearly with the logarithm of concentration of tDNA in the range from 1.0 × 10−17to 1.0 × 10−12M with a detection limit of 4.28 × 10−19M (S/N = 3). The DNA biosensor showed the advantage of acceptable selectivity, good stability and fabrication reproducibility. The proposed DNA biosensor was applied for tDNA detection in a real biological sample, and good recoveries were obtained from 95.61 to 101.8%.