One major marker of nitrosative stress is the formation of 3-Nitrotyrosine (3-NT) from Tyrosine (Tyr) by adding a nitro group (-NO₂) with nitrating agents. Nitration of Tyr often causes loss of protein activity and is linked with many diseases. In this article, we detect 3-NT and discriminate it from Tyr with Differential Pulse Voltammetry (DPV) as it is a very important biomarker. We first examined redox (oxidation/reduction) properties and stability of 3-NT in detail. Second, we provided the Tyr and 3-NT discrimination with DPV and compared with the chromatography. We then explored the interaction of 3-NT and DNA oligonucleotides. Our findings demonstrate that 3-NT can be used as a new electrochemical indicator, which is able to detect hybridization of probe (single stranded DNA-ssDNA) and hybrid (double stranded DNA-dsDNA) both via 3-NT reduction and guanine oxidation signal changes at the same time. The signal differences enabled us to distinguish ssDNA and dsDNA without using a label or a tag. Moreover, we achieved to detect hybridization of DNA by using the reduction signal of 3-NT obtained at −0.4 V vs. Ag/AgCl. More importantly, we observed the changes of the reduction signals of 3-NT after the interaction of probe and hybrid sequences. We showed that 3-NT signal decreases more with hybrid than the probe. Our platform, for the first time, demonstrates the detection of hybridization both guanine oxidation and indicator reduction signal changes at the same time. Moreover, we, for the first time, demonstrated the interaction between 3-NT and DNA.

亚硝化胁迫的一个主要标志是通过添加硝基（-NO ₂）由酪氨酸（Tyr）形成3-硝基酪氨酸（3-NT））与硝化剂。酪氨酸的硝化通常会导致蛋白质活性下降，并与许多疾病有关。在本文中，我们检测到3-NT并通过差分脉冲伏安法（DPV）将其与Tyr区别开来，因为它是非常重要的生物标志物。我们首先详细研究了3-NT的氧化还原（氧化/还原）性质和稳定性。其次，我们用DPV提供了Tyr和3-NT的鉴别结果，并与色谱法进行了比较。然后，我们探索了3-NT和DNA寡核苷酸的相互作用。我们的发现表明3-NT可以用作新的电化学指示剂，它能够通过3-NT还原和鸟嘌呤氧化信号检测探针（单链DNA-ssDNA）和杂交体（双链DNA-dsDNA）的杂交同时更改。信号差异使我们能够在不使用标签或标签的情况下区分ssDNA和dsDNA。此外，我们实现了通过使用在-0.4 V相对于Ag / AgCl的条件下获得的3-NT还原信号来检测DNA的杂交。更重要的是，我们观察到探针和杂合序列相互作用后3-NT还原信号的变化。我们显示，与探针相比，杂合体的3-NT信号下降更多。我们的平台首次展示了同时检测鸟嘌呤氧化和指示剂还原信号变化的杂交检测。而且，我们首次证明了3-NT和DNA之间的相互作用。我们观察到探针和杂合序列相互作用后3-NT还原信号的变化。我们表明，与探针相比，杂合体的3-NT信号下降更多。我们的平台首次展示了同时检测鸟嘌呤氧化和指示剂还原信号变化的杂交检测。而且，我们首次证明了3-NT和DNA之间的相互作用。我们观察到探针和杂合序列相互作用后3-NT还原信号的变化。我们表明，与探针相比，杂合体的3-NT信号下降更多。我们的平台首次展示了同时检测鸟嘌呤氧化和指示剂还原信号变化的杂交检测。而且，我们首次证明了3-NT和DNA之间的相互作用。