Gu Tingting, Xia Hong-Qi, Hu Yue, Jiang Yongqi
School of Chemical Engineering, University of Science and Technology Liaoning.
Anal Sci. 2018 Oct 10;34(10):1131-1135. doi: 10.2116/analsci.18P167. Epub 2018 Jun 1.
A reagent-less electrochemical DNA biosensor for rapid non-electroactive polycyclic organic compounds (POCs) screening and detection was proposed. In this method, methylene blue (MB) was incorporated into DNA/chitosan polyion complex membrane and then modified onto a glassy carbon electrode (GCE). The electrochemical analysis for the prepared DNA-MB/chitosan/GCE showed that the modified electrode exhibited high electrochemical activity and stability. The addition of tetracycline hydrochloride (TC), a model analyte of non-electroactive POCs, resulted in an obvious peak current decrease in DNA-MB/chitosan/GCE, and this electrochemical response was affected by the DNA type and MB/DNA ratio in the modified electrodes. Ultraviolet-visible (UV-Vis) absorption spectroscopy was utilized to furthermore investigate the interaction between TC and DNA-MB/chitosan/GCE. As a result, a competitive interaction and displacement effect between TC and the intercalated MB was proposed. In our condition, the prepared DNA-MB/chitosan/GCE showed high sensitivity to POCs and had almost no response to common interferences. Besides, the good stability and reproducibility of the prepared electrode made it suitable for practical use.
提出了一种用于快速筛选和检测非电活性多环有机化合物（POCs）的无试剂电化学DNA生物传感器。该方法将亚甲基蓝（MB）掺入DNA/壳聚糖聚离子复合膜中，然后修饰在玻碳电极（GCE）上。对制备的DNA-MB/壳聚糖/GCE进行的电化学分析表明，修饰电极具有高电化学活性和稳定性。加入非电活性POCs的模型分析物盐酸四环素（TC）后，DNA-MB/壳聚糖/GCE的峰电流明显降低，且这种电化学响应受修饰电极中DNA类型和MB/DNA比例的影响。利用紫外可见（UV-Vis）吸收光谱进一步研究了TC与DNA-MB/壳聚糖/GCE之间的相互作用。结果表明，TC与插入的MB之间存在竞争相互作用和置换效应。在我们的条件下，制备的DNA-MB/壳聚糖/GCE对POCs具有高灵敏度，对常见干扰几乎无响应。此外，制备电极良好的稳定性和重现性使其适用于实际应用。
