A rapid signal amplified DNA detection method based on self-replicating catalyzed hairpin assembly (SRCHA) has been proposed. In this SRCHA system, two split target DNA sequences were respectively integrated into hairpin auxiliary probes H1 and H2. H2 was used as fluorescent probe which containing a fluorescent nucleotide base analog pyrrolo-deoxycytidine (P-dC) at the end of the stem. Target DNA can be circularly used in this SRCHA system to form the helix DNA H1-H2 complex, the structure change of H2 will move P-dC from hairpin stem to flexible ssDNA sticky end, leading to fluorescence increase due to the less stacking interaction. Meanwhile, the two spilt target DNA sequence was reunited and the target DNA replicate was obtained, which also can be circularly used as new activator to trigger additional CHA reaction and fluorescence signal was then rapidly and significantly enhanced. This SRCHA system has been successfully employed for DNA detection with picomolar within around 15 min, and provides a potential technology for the real-time rapid bioanalysis.

提出了一种基于自我复制催化发夹装配（SRCHA）的快速信号放大DNA检测方法。在该SRCHA系统中，两个分裂的靶DNA序列分别整合到发夹辅助探针H1和H2中。H2用作荧光探针，其在茎的末端包含荧光核苷酸碱基类似物吡咯并-脱氧胞苷（P-dC）。靶DNA可以在此SRCHA系统中循环使用，以形成螺旋DNA H1-H2复合物，H2的结构变化会将P-dC从发夹茎移至柔性ssDNA粘性末端，由于较少的堆叠相互作用而导致荧光增加。同时，将两个溢出的靶DNA序列重新结合，获得了靶DNA的重复片段，它也可以循环用作新的激活剂来触发额外的CHA反应，然后荧光信号迅速显着增强。该SRCHA系统已成功用于约15分钟内的皮摩尔DNA检测，并为实时快速生物分析提供了潜在技术。