In this work, a novel fluorescent DNA sensor system based on polydopamine (PDA) modified layered double hydroxides (Mg/Al-LDH) was designed and PDA-co-LDH composites were examined for DNA sensing owing to their fluorescence quenching capability. We demonstrated that the fluorescence of ssNDA could be effectively quenched after mixing with PDA-co-LDH composites, while the fluorescence could be recovered after the target DNA was added to form dsDNA. Based on the fluorescence changes, the target DNA can be facilely and quantitatively determined by the DNA sensor system. Based on 3σ method, the detection limit is calculated to be as low as 1.0 pM. Moreover, PDA-co-LDH composites have an excellent sensitivity and selectivity that can discriminate the complementary and mismatched target sequences even for the single-base mismatched target sequences. More importantly, this DNA sensor system could be expected for detection of many other molecules through design DNA sequences.

在这项工作中，设计了一种基于聚多巴胺（PDA）修饰的层状双氢氧化物（Mg / Al-LDH）的新型荧光DNA传感器系统，并检查了PDA- co -LDH复合材料的荧光猝灭能力，以进行DNA传感。我们证明，与PDA- co -LDH复合材料混合后，ssNDA的荧光可以有效地淬灭，而加入目标DNA形成dsDNA后，荧光可以回收。基于荧光变化，可以通过DNA传感器系统轻松，定量地确定目标DNA。基于3σ方法，计算出的检出限低至1.0 pM。此外，PDA- co-LDH复合物具有出色的灵敏度和选择性，即使对于单碱基错配的靶序列，也可以区分互补和错配的靶序列。更重要的是，这种DNA传感器系统有望通过设计DNA序列检测许多其他分子。