Signal amplification plays a significant role in nucleic acid analysis, especially in trace nucleic acid detection. Transcription-based signal amplification is a very important component in the field of signal amplification, and has received extensive attention depending on outstanding cyclic transcription ability. However, the low efficiency of transcription caused by limited template length usually restricts their further applications significantly. Herein, we developed a transcription-based signal amplification method with high sensitivity and selectivity. The approach we proposed couples the advantageous features of long template synthesis from phosphorothioated-terminal hairpin formation and self-priming extension (PS-THSP) with self-amplification from cell-free transcription system. The results demonstrate that this approach can be applied to quantify T4 Polynucleotide Kinase (T4 PNK) phosphatase activity in a broad range from 0.00001 to 0.01 U/mL, with a detection limit of 8.1 × 10^-6 U/mL. Moreover, this device can be further employed as a superior signal amplification platform for the detection of other analytical targets after moderate modifications.

信号放大在核酸分析中发挥着重要作用，尤其是在痕量核酸检测中。基于转录的信号放大是信号放大领域中非常重要的组成部分，凭借其出色的循环转录能力而受到广泛关注。然而，由于模板长度有限导致的转录效率低，通常会极大地限制它们的进一步应用。在此，我们开发了一种具有高灵敏度和选择性的基于转录的信号放大方法。我们提出的方法将来自硫代磷酸酯末端发夹形成和自引发延伸 (PS-THSP) 的长模板合成的有利特征与来自无细胞转录系统的自扩增相结合。^-6单位/毫升。此外，该装置可进一步用作优良的信号放大平台，用于在适度修改后检测其他分析目标。