【摘要】 以自制的丝网印刷碳电极（SPCE）为基体电极,利用DNA四面体纳米探针和酶催化信号放大构建了一个一次性电化学阻抗型RNA传感器.固定在AuNPs修饰的SPCE表面的DNA四面体结构能确保DNA探针具有可控的密度和方向,结合辣根过氧化物酶（HRP）催化H₂O₂氧化4-氯-1-萘酚（CN）的反应,生成不溶物沉积在电极表面,有效地放大电化学阻抗信号,实现了miRNA的高灵敏阻抗测定.检测限可以低至1.0 pmol/L,阻抗值和miRNA-141浓度的对数在3.0～1 000 pmol/L之间具有良好的定量关系.更多还原

【Abstract】 A disposable electrochemical impedance RNA sensor was fabricated based on homemade screen printed carbon electrode（SPCE） and enzyme-catalyzed signal amplification reaction. The SPCE was modified with AuNPs through electrodeposition and subsequently functionalized with-SH of the DNA nanostructure, which can ensure that the DNA probe has a controllable density and direction. Hydrogen peroxide（HRP） can catalyze oxidation reaction of H₂O₂ and 4-chloro-1-naphthol（CN） to produce an insoluble precipitate accumulated on the electrode surface, which caused the electron-transfer resistance of the sensor increased greatly. According to the above, signal amplification detection of the target microRNA can be carried out. The proposed method could detect target miRNA at a linear range from 3.0 pmol/L to 1 000 pmol/L, with a detection limit of 1.0 pmol/L.更多还原