AbstractThe authors describe a DNA based voltammetric assay for the cancer biomarker microRNA-25. A glassy carbon electrode (GCE) was modified with amino-functionalized graphene quantum dots and used as an amplifier of electrochemical signals. p-Biphenol is introduced as a new electroactive probe with a fairly low working potential of 0.3 V (vs. Ag/AgCl). The stages of fabricating the electrode were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. ss-Probe DNA was immobilized on the modified GCE and then exposed to a sample containing microRNA-25. The results indicated that the electrode can distinguish complementary microRNA-25 from a single-base mismatch. The increase in the electrochemical response of PBP and the positive shift in the potential peak indicate that PBP is intercalated between two strands. Under optimized experimental conditions, the current of the electrode increases linearly with the logarithm of the microRNA-25 concentration in the range from 0.3 nM to 1.0 μM, and the detection limit is 95.0 pM. The assay was successfully employed to the determination of microRNA-25 in spiked human plasma. Graphical abstractA novel electrochemical nanogenosensor is introduced for simple and sensitive determination of microRNA-25, as a biomarker, based on amino-functionalized graphene quantum dots (as a surface modifier) and p-biphenol (as an electroactive label).

中文翻译：

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基于使用氨基功能化石墨烯量子点和 ss- 和 ds-DNA 作为基因探针的 microRNA-25 伏安分析

摘要作者描述了癌症生物标志物 microRNA-25 的基于 DNA 的伏安分析。玻碳电极（GCE）用氨基功能化的石墨烯量子点修饰，用作电化学信号的放大器。p-Biphenol 作为一种新的电活性探针引入，具有 0.3 V（相对于 Ag/AgCl）的相当低的工作电位。电极的制造阶段通过循环伏安法和电化学阻抗谱来表征。ss-Probe DNA 固定在修饰的 GCE 上，然后暴露于含有 microRNA-25 的样品中。结果表明电极可以区分互补的 microRNA-25 和单碱基错配。PBP 电化学响应的增加和电位峰的正移表明 PBP 介于两条链之间。在优化的实验条件下，电极电流在0.3 nM至1.0 μM范围内随microRNA-25浓度的对数线性增加，检测限为95.0 pM。该测定已成功用于测定加标人血浆中的 microRNA-25。图形摘要基于氨基功能化石墨烯量子点（作为表面改性剂）和对双酚（作为电活性标记），引入了一种新型电化学纳米基因传感器，用于简单而灵敏地测定作为生物标志物的 microRNA-25。该测定已成功用于测定加标人血浆中的 microRNA-25。图形摘要基于氨基功能化石墨烯量子点（作为表面改性剂）和对双酚（作为电活性标记），引入了一种新型电化学纳米基因传感器，用于简单而灵敏地测定作为生物标志物的 microRNA-25。该测定已成功用于测定加标人血浆中的 microRNA-25。图形摘要基于氨基功能化石墨烯量子点（作为表面改性剂）和对双酚（作为电活性标记），引入了一种新型电化学纳米基因传感器，用于简单而灵敏地测定作为生物标志物的 microRNA-25。