Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710127, China.
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710127, China.
Anal Chim Acta. 2023 Sep 1;1272:341522. doi: 10.1016/j.aca.2023.341522. Epub 2023 Jun 10.
The interesting adsorption affinity of two-dimensional nanosheets to single stranded over double stranded nucleic acids have stimulated the exploration of these materials in biosensing. Herein, MoS nanosheets decorated anodic aluminum oxide (AAO) membrane was simply prepared by suction filtration. The MoS/AAO hybrid membrane was initially applied to the electrochemical detection of microRNA using let-7a as the model. When let-7a was incubated with its complementary DNA, double stranded DNA-RNA formed and which displayed weak adsorption capability to the hybrid membrane. And thus the steric effect combining the electrostatic repulsion of the backbone phosphate of nucleic acids for [Fe(CN)] transport across the hybrid membrane varied with the concentration of let-7a. In this way, a label-free electrochemical detection method for microRNA was established by monitoring the change of the redox current of [Fe(CN)]. To further improve the detection sensitivity of the method, we proposed two separate strategies focusing on the amplification of the target-induced steric hindrance with DNA nanostructure and the magnification of the electrode sensitivity for [Fe(CN)] by electrode modification. By using the two strategies, the hybrid membrane based-detection method exhibited broad linear range, low detection limit and good selectivity as well as reproducibility. Therefore, this study provided a proof-of-concept for the application of two-dimensional material to nucleic acids detection.
二维纳米片对单链和双链核酸具有有趣的吸附亲和力，这激发了人们对这些材料在生物传感中的探索。在此，通过抽滤简单制备了 MoS 纳米片修饰的氧化铝纳米管（AAO）膜。首先将 MoS/AAO 杂化膜应用于微 RNA 的电化学检测，以 let-7a 为模型。当 let-7a 与其互补 DNA 孵育时，形成双链 DNA-RNA，其对杂化膜显示出较弱的吸附能力。因此，结合核酸骨架磷酸盐静电排斥的空间位阻效应，影响[Fe(CN)]穿过杂化膜的传输，其变化与 let-7a 的浓度有关。通过监测[Fe(CN)]的氧化还原电流变化，建立了一种无标记的电化学检测微 RNA 的方法。为了进一步提高该方法的检测灵敏度，我们提出了两种策略，即利用 DNA 纳米结构放大目标诱导的空间位阻和通过电极修饰放大[Fe(CN)]的电极灵敏度。通过使用这两种策略，基于杂化膜的检测方法表现出较宽的线性范围、较低的检测限、良好的选择性和重现性。因此，本研究为二维材料在核酸检测中的应用提供了概念验证。
