近日，武汉大学王富安团队报道了通过滚环实现自主指数扩增——DNAzyme反馈编程。相关论文于2025年11月26日发表在《美国化学会志》上。

滚环扩增（RCA）是一种强大的等温核酸检测策略，但其线性动力学及对外部引物的依赖限制了灵敏度和可编程性。

研究组报道了一种指数级滚环扩增（E-RCA）平台，将引物再生与信号放大整合到单一DNA编码系统中。该设计采用编码I-R3自切割DNA酶序列的环形DNA模板；在RCA过程中，DNA扩增产物中生成串联的I-R3单元，随后催化位点特异性切割以释放新引物。这一自维持的（RCA ↔ DNA酶）扩增回路仅需环形DNA探针和DNA聚合酶即可实现稳健的指数级信号增长，无需外部引物或蛋白酶。

研究组通过生化实验和动力学模型阐明了其机制，并在多路复用细胞内微RNA成像及临床乳腺癌组织定量双标记分析中验证了该系统。E-RCA策略实现了高诊断准确性（AUC = 0.914；特异性 = 100%；敏感性 = 81.3%），展示了其在生物和临床场景中用于灵敏、可编程且自主的分子分析的潜力。

附：英文原文

Title: Autonomous Exponential Amplification via Rolling Circle–DNAzyme Feedback Programming

Author: Jinhua Shang, Mengdi Yu, Yifei Wang, Shanshan Yu, Xianzheng Zhang, Fuan Wang, Yingfu Li

Issue&Volume: November 26, 2025

Abstract: Rolling circle amplification (RCA) is a powerful isothermal strategy for nucleic acid detection, but its linear kinetics and dependence on externally supplied primers limit its sensitivity and programmability. Here, we report an exponential RCA (E-RCA) platform that integrates primer regeneration and signal amplification into a single DNA-encoded system. The design uses a circular DNA template encoding the I-R3 self-cleaving DNAzyme sequence; during RCA, tandem I-R3 units are generated within the DNA amplicons, which then catalyze site-specific cleavage to release new primers. This self-sustained (RCA DNAzyme) amplification circuit enables robust exponential signal growth using only a circular DNA probe and a DNA polymerase without requiring external primers or protein enzymes. We elucidate the mechanism through biochemical experiments and kinetic modeling and validate the system in multiplexed intracellular microRNA imaging and quantitative dual-marker profiling of clinical breast cancer tissues. The E-RCA strategy achieved high diagnostic accuracy (AUC = 0.914; specificity = 100%; sensitivity = 81.3%), demonstrating its potential for sensitive, programmable, and autonomous molecular analysis in both biological and clinical contexts.

DOI: 10.1021/jacs.5c12435

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c12435