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利用纳米金膜(GNF)和稳定的Y型DNA成功构建了一种具有良好选择性和较低检测限的DNA传感器.首先将金电极快速氧化后还原制成GNF,利用Au—S键将捕获探针DNA(c-DNA)有效地固定到GNF电极表面,在目标物存在的情况下,将其与标记有亚甲蓝(MB)的指示探针(r-DNA)杂交形成Y型结构.利用GNF独特的纳米性质和形成的Y型DNA结构特点,使MB接近GNF,从而提高了电子传递速率,以差分脉冲伏安法(DPV)实现DNA特定序列的检测,检测线性范围为1.0×10-12～1.0×10-9mol/L,检测下限为2.4×10-13mol/L.与传统的传感器相比,本方法提高了选择性,减小了背景电流.此外,该传感器表现出良好的重现性和稳定性.
A new kind of DNA sensor with good selectivity and low detection limit was successfully constructed by using gold nanoparticle (GNF) and stable Y-DNA.First, the gold electrode was oxidized and then reduced to GNF, and the Au-S bond was used to capture Probe DNA (c-DNA) is effectively immobilized to the surface of the GNF electrode, which in the presence of the target hybridizes to the indicator probe (r-DNA) labeled with methylene blue (MB) to form a Y-type structure. Using GNF’s unique nano-nature and Y-shaped DNA structure, GN approached GNF to improve the electron transfer rate. The detection of specific DNA sequences by differential pulse voltammetry (DPV) was carried out. The linear range was 1.0 × 10 -12 ~ 1.0 × 10-9mol / L, the detection limit of 2.4 × 10-13mol / L. Compared with the traditional sensor, the method increased the selectivity, reducing the background current.In addition, the sensor showed good Reproducibility and stability.