Department of Clinical Laboratory, Affiliated Hospital of Nantong University, Nantong, Jiangsu, 226001, People's Republic of China.
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, People's Republic of China.
Mikrochim Acta. 2019 Jan 16;186(2):116. doi: 10.1007/s00604-018-3204-9.
An electrochemical biosensor for microRNA was constructed on the basis of direct growth of electroactive Prussian Blue (PB) on graphene oxide (GO). A mercapto-modified probe DNA that is complementary to the hepatocellular carcinoma biomarker microRNA-122 was firstly anchored on a gold electrode (AuE). Then, GO (with its large surface and multiple active sites) was adsorbed on probe DNA through π-interaction. Subsequently, the PB nanoparticles were directly grown on GO via alternative dipping the electrode in solutions of FeCl and hexacyanoferrate(III). Upon incubation of the resulting electrode with a solution of microRNA-122, the probe DNA on the electrode interacts with microRNA-122 to form a rigid duplex. This results in the release of electroactive PB/GO from the sensing interface and a decrease in current, typically measured at 0.18 V (vs. Ag/AgCl (3 M KCl)). The sensor covers the 10 fM to 10 nM microRNA-122 concentration range and has a 1.5 fM detection limit. The method was successfully applied to the determination of microRNA-122 in real biological samples. Graphical abstract Graphene oxide with in-situ grown Prussian Blue is applied as an electrochemical probe for the analysis of microRNA-122.
基于普鲁士蓝（PB）在氧化石墨烯（GO）上的直接生长，构建了用于 microRNA 的电化学生物传感器。首先将巯基修饰的探针 DNA 固定在金电极（AuE）上，该探针 DNA 与肝癌生物标志物 microRNA-122 互补。然后，GO（具有较大的表面积和多个活性位点）通过π-相互作用吸附在探针 DNA 上。随后，通过交替将电极浸入 FeCl 和铁氰化钾(III)溶液中，将 PB 纳米粒子直接生长在 GO 上。将所得电极与 microRNA-122 溶液孵育后，电极上的探针 DNA 与 microRNA-122 相互作用形成刚性双链体。这导致电活性 PB/GO 从传感界面释放，并导致电流减小，通常在 0.18 V（相对于 Ag/AgCl（3 M KCl））下测量。该传感器涵盖 10 fM 至 10 nM microRNA-122 浓度范围，检测限为 1.5 fM。该方法成功应用于实际生物样品中 microRNA-122 的测定。 示意图 原位生长普鲁士蓝的氧化石墨烯被用作分析 microRNA-122 的电化学生物探针。
