Department of Chemistry, College of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212100, PR China.
Department of Chemistry, College of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212100, PR China.
Biosens Bioelectron. 2021 Nov 1;191:113393. doi: 10.1016/j.bios.2021.113393. Epub 2021 Jun 8.
In this article, we developed a novel ECL ratiometry on a closed bipolar electrode (BPE) for the sensitively and accurately detection of miRNA-21. High quantum yield and low toxicity BNQDs was synthesized and coated at BPE cathode as an ECL emitter, while the anode of BPE was calibrated via another ECL material, Ir(df-ppy)(pic) (Firpic). The electron neutrality at both ends of the BPE electrically coupled the reactions on each pole of the BPE. Therefore, one electrochemical sensing reaction could be quantified at one end of the BPE. By the hybridization of target miRNA-21 and hairpin, the glucose blocked in MSNs by the hairpin was released and reacted with glucose oxidase (GOD) to generate HO, thereby reducing the ECL signal of the cathode BNQDs/KSO system and promoting ECL signal of anode Firpic/TPrA. Further, the G-quadruplex formed by unreacted hairpin bases consumed HO, which not only recovered the ECL of BNQDs, but also further improved the ECL emission of Firpic. Therefore, the concentration of miRNA-21 could be measured by the ECL ratio of BNQDs and Firpic. The data showed that the detection limit was 10 M (S/N = 3) with the linear range of 10 M to 10 M. The strategy of the BPE-ECL ratio method based on BNQDs showed a good prospect in clinical application.
在本文中，我们开发了一种基于闭双极电极（BPE）的新型 ECL 比率法，用于灵敏且准确地检测 miRNA-21。合成了具有高量子产率和低毒性的 BNQDs，并将其涂覆在 BPE 阴极作为 ECL 发射器，而 BPE 的阳极则通过另一种 ECL 材料 Ir(df-ppy)(pic)（Firpic）进行校准。BPE 两端的电子中性使 BPE 每个极上的反应电耦合。因此，可以在 BPE 的一端定量测量一个电化学传感反应。通过目标 miRNA-21 和发夹的杂交，发夹使 MSNs 中被阻断的葡萄糖被释放出来并与葡萄糖氧化酶（GOD）反应生成 HO，从而降低阴极 BNQDs/KSO 体系的 ECL 信号并促进阳极 Firpic/TPrA 的 ECL 信号。此外，未反应的发夹碱基形成的 G-四链体消耗 HO，这不仅恢复了 BNQDs 的 ECL，而且进一步提高了 Firpic 的 ECL 发射。因此，可以通过 BNQDs 和 Firpic 的 ECL 比率来测量 miRNA-21 的浓度。数据显示，检测限为 10 nM（S/N = 3），线性范围为 10 nM 至 10 μM。基于 BNQDs 的 BPE 电化学比率方法的策略在临床应用中具有广阔的前景。
