Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, School of Chemistry & Chemical Engineering, Anhui University, Hefei 230601, P. R. China.
J Mater Chem B. 2020 Mar 25;8(12):2471-2475. doi: 10.1039/c9tb02773d.
A novel electrochemiluminescence (ECL) biosensor was developed in this study, which was based on the Ag-NP modified tetrahedral DNA nanostructure. First, a stable and rigid three-dimensional tetrahedral DNA nanostructure (TDN) was modified on a gold electrode, which was used as a capture element. The TDN improves the accuracy and sensitivity of this biosensor. In addition, silver nanoparticles (Ag NPs) with excellent electrical conductivity were introduced on the edges of TDNs to enhance the ECL intensity of the metal-organic framework (MOF) nanomaterial. Apart from imparting conductivity, the Ag NPs can also act as co-reactant accelerators to enhance the ECL intensity. A Eu3+ doped Zr-MOF material (Eu@MOF) was proposed and used as an ECL material for the first time. Terminal phosphate-modified MUC1 aptamer DNA bonded with the exposed Zr nodes on the surface of MOFs through Zr-O-P bonds to construct the DNA-Eu@MOF signal element. Based on the Ag NP-modified TDN capture element and the DNA-Eu@MOF signal element, a hypersensitive biosensor was established. Under the optimal conditions, this biosensor exhibited a wide detection range from 1.135 fg mL-1 to 0.1135 ng mL-1 and a low detection limit of 0.37 fg mL-1 (S/N = 3) toward the target MUC1. The biosensor also showed excellent stability and high selectivity for MUC1 detection.
本研究构建了一种基于 Ag-NP 修饰的四面体形 DNA 纳米结构的新型电化学发光（ECL）生物传感器。首先，在金电极上修饰了稳定且刚性的三维四面体 DNA 纳米结构（TDN），作为捕获元件。TDN 提高了该生物传感器的准确性和灵敏度。此外，在 TDN 的边缘引入了具有优异导电性的银纳米颗粒（Ag NPs），以增强金属有机骨架（MOF）纳米材料的 ECL 强度。Ag NPs 除了赋予导电性外，还可以作为共反应物加速剂来增强 ECL 强度。首次提出并使用 Eu3+掺杂的 Zr-MOF 材料（Eu@MOF）作为 ECL 材料。末端磷酸化修饰的 MUC1 适体 DNA 通过 Zr-O-P 键与 MOFs 表面暴露的 Zr 节点结合，构建 DNA-Eu@MOF 信号元件。基于 Ag NP 修饰的 TDN 捕获元件和 DNA-Eu@MOF 信号元件，建立了高灵敏度的生物传感器。在最佳条件下，该生物传感器对目标 MUC1 的检测范围从 1.135 fg mL-1 到 0.1135 ng mL-1，检测限低至 0.37 fg mL-1（S/N = 3）。该生物传感器还表现出对 MUC1 检测的优异稳定性和高选择性。
