In this work, a novel electrochemical biosensor based on nitronyl nitroxide monoradical 2,2,6,6-tetramethylpiperidine 1-Oxyl (TEMPO) as new electrochemical label for facile nucleic acids detection is developed. This fast and convenient functional microelectrode was designed by fixing the capture probe peptide nucleic acid (PNA) and using the coordination interaction of Zr4+ with both phosphate groups and carboxyl groups. Differential pulse voltammetry (DPV) was used to study the oxidation current of TEMPO which was combined with the electrode surface and labeled. TEMPO electrochemical signal related to target deoxyribonucleic acid (tDNA) concentration was finally detected when tDNA was added on the surface of glassy carbon electrode (GCE). The detection principle, optimization of key factors and performance analysis of the biosensor are also discussed. A great linear relation is acquired within the scope of 10 pM-100 nM under optimal conditions and the detection limit of this experiment is calculated as low as 2.57 pM (R2 = 0.996). In addition, complex serum samples were used to explore the practical application of this experiment. The results show the developed electrochemical DNA biosensor has wide application prospects in nucleic acids detection and clinical analysis.

中文翻译：

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硝基氮氧单自由基 TEMPO 作为用于核酸超灵敏检测的新型电化学标记

在这项工作中，开发了一种基于硝酰基氮氧单自由基 2,2,6,6-四甲基哌啶 1-Oxyl (TEMPO) 作为新型电化学标记的新型电化学生物传感器，用于简便的核酸检测。这种快速方便的功能性微电极是通过固定捕获探针肽核酸 (PNA) 并利用 Zr4+ 与磷酸基团和羧基基团的配位相互作用而设计的。差分脉冲伏安法（DPV）用于研究TEMPO与电极表面结合并标记的氧化电流。当在玻碳电极 (GCE) 表面添加 tDNA 时，最终检测到与目标脱氧核糖核酸 (tDNA) 浓度相关的 TEMPO 电化学信号。检测原理，还讨论了生物传感器关键因素的优化和性能分析。在最佳条件下，在 10 pM-100 nM 范围内获得了很好的线性关系，本实验的检测限计算低至 2.57 pM (R2 = 0.996)。此外，还使用复杂的血清样本来探索该实验的实际应用。结果表明，所研制的电化学DNA生物传感器在核酸检测和临床分析方面具有广泛的应用前景。