Highly sensitive electrochemical DNA sensor based on the use of three-dimensional nitrogen-doped graphene
Highly sensitive electrochemical DNA sensor based on the use of three-dimensional nitrogen-doped graphene
复制标题
基于三维氮掺杂石墨烯的高灵敏度电化学DNA传感器
DOI：
10.1007/s00604-017-2588-2
复制
发表时间：
2018-01-01
影响因子：
5.7
通讯作者：
Tang, Jiali
中科院分区：
文献类型：
--
作者：
Chen, Mei;Su, Huilan;Tang, Jiali
本文介绍了一种灵敏测定DNA特定序列的伏安法。该测定基于三维氮掺杂石墨烯（3D-NG），由于其优异的导电性，其提供了有利的微环境以保持固定化探针单链DNA的活性，并且还促进电子转移。采用扫描电子显微镜、拉曼光谱、X射线光电子能谱、循环伏安法和电化学阻抗谱等方法对自支撑3D-NG电极进行表征。以亚甲基蓝为电化学指示剂，采用微分脉冲伏安法对DNA杂交进行监测。在最佳条件下，峰电流（最佳测量电压为0.28 V vs. Ag/AgCl）与10 f中ssDNA浓度的对数呈线性增加。至10 nM浓度范围内，具有3.5 f.检测限（信噪比为3）。该生物传感器对ssDNA具有良好的选择性，甚至可以区分单碱基错配。该方法具有良好的重现性和稳定性，具有良好的临床应用前景。
This paper describes a voltammetric method for sensitive determination of specific sequences of DNA. The assay is based on three-dimensional nitrogen-doped graphene (3D-NG) which, due to its excellent electrical conductivity, provides a favorable microenvironment to retain the activity of immobilized probe single-stranded DNA and also facilitates electron transfer. The free-standing 3D-NG electrode was characterized by scanning electron microscopy, Raman and X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Differential pulse voltammetry was applied to monitor DNA hybridization using Methylene Blue as an electrochemical indicator. Under optimal conditions, the peak currents (best measured at 0.28 V vs. Ag/AgCl) increase linearly with the logarithm of the concentrations of ssDNA in the 10 f. to 10 nM concentrations range, with a 3.5 f. detection limit (at a signal/noise ratio of 3). The biosensor exhibits good selectivity for ssDNA and can distinguish even single-base mismatches. The capability of the method was tested with spiked serum samples, and excellent reproducibility and stability is found. This indicates that the strategy is promising for use in clinical applications.