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制备了基于氧化锆(ZrO2)/聚中性红(PNR)修饰电极的电化学DNA传感器。探针DNA通过磷酸基和ZrO2的相互作用组装到电极表面。原子力显微镜(AFM)和电化学方法用于电极的表征。PNR在DNA杂交前后峰电流的变化作为杂交信号,用示差脉冲伏安法对转基因植物CaMV35S启动子基因片段进行测定。结果表明:探针DNA和完全互补的DNA片段杂交后,杂交信号明显变小,峰电流的变化值与其浓度的对数在1.0×10-11~1.0×10-8mol/L范围内呈良好的线性关系,检出限为3.46×10-12mol/L(S/N=3)。此外,传感器能区分互补、单碱基错配、完全错配的DNA序列,已用于样品的测定。
An electrochemical DNA sensor based on zirconia (ZrO2) / poly neutral red (PNR) modified electrodes was prepared. Probe DNA is assembled to the electrode surface through the interaction of phosphate groups and ZrO2. Atomic force microscopy (AFM) and electrochemical methods were used to characterize the electrodes. PNR peak change in DNA before and after hybridization as a hybridization signal, with differential pulse voltammetry CaMV35S promoter gene fragments of transgenic plants were determined. The results showed that the hybridization signal between the probe DNA and the completely complementary DNA was obviously smaller, and the change of peak current and the logarithm of the concentration were good in the range of 1.0 × 10-11 ~ 1.0 × 10-8 mol / L The linear relationship between the detection limits was 3.46 × 10-12mol / L (S / N = 3). In addition, the sensor can distinguish between complementary, single base mismatch, completely mismatched DNA sequences have been used for the determination of the sample.