Anhui Key Laboratory of Chemo/Biosensing, College of Chemistry and Materials Science , Anhui Normal University , Wuhu 241000 , P. R. China.
Anal Chem. 2019 Jun 18;91(12):7965-7970. doi: 10.1021/acs.analchem.9b02025. Epub 2019 Jun 7.
Solid-state nanopores have been employed as useful tools for single molecule analysis due to their advantages of easy fabrication and controllable diameter, but selectivity is always a big concern for complicated samples. In this work, functionalized magnetic core-shell FeO-Au nanoparticles, which acted as a molecular carrier, were introduced into nanopore electrochemical system for microRNA sensing in complicated samples with high sensitivity, selectivity and signal-to-noise ratio (SNR). This strategy is based on the specific affinity between neutral peptide nucleic acids (PNA)-modified FeO-Au nanoparticles and negative miRNA, and the formation of negative FeO-Au-PNA-miRNA complex, which can pass through the nanopore by application of a positive potential and eliminate neutral FeO-Au-PNA complex. To detect miRNA in complicated samples, a magnet has been used to separate FeO-Au-PNA-miRNA complex with good selectivity. We think this is a facile and effective method for the detection of different targets at single molecular level, including nucleic acids, proteins, and other small molecules, which will open up a new approach in the nanopore sensing field.
固态纳米孔由于其易于制造和可控制直径的优点，已被用作单分子分析的有用工具，但选择性一直是复杂样品的一个大问题。在这项工作中，功能化的磁性核壳 FeO-Au 纳米粒子作为分子载体被引入到纳米孔电化学系统中，用于复杂样品中 microRNA 的高灵敏度、选择性和信噪比 (SNR) 检测。该策略基于中性肽核酸 (PNA) 修饰的 FeO-Au 纳米粒子与负 miRNA 之间的特异性亲和力，以及负的 FeO-Au-PNA-miRNA 复合物的形成，该复合物可以通过施加正电势穿过纳米孔，并消除中性的 FeO-Au-PNA 复合物。为了在复杂样品中检测 miRNA，使用磁铁来分离具有良好选择性的 FeO-Au-PNA-miRNA 复合物。我们认为，这是一种在单分子水平上检测不同靶标（包括核酸、蛋白质和其他小分子）的简便有效的方法，这将为纳米孔传感领域开辟新途径。
