RNA-cleaving DNAzymes possess important roles in DNAzymes and have been widely used in the biosensors, DNA nanomachines owing to their ion-specific dependence. However, there are still challenges in constructing universal but versatile stimuli-responsive strategies of RNA-cleaving DNAzymes. Herein, a stimuli-responsive strategy for RNA-cleaving DNAzyme is proposed by the artful design of hairpin nanostructure, in which the activities of DNAzyme (Pb²⁺-dependent DNAzyme as a model) in the hairpin’s loop are pH-regulated by using the triplex stem as the “lock”. Upon introducing the “key”, pH values, the DNAzyme will be activated and fragment the substrate of it in the presence of Pb²⁺, accompanied by the turn-on of the fluorescence quenched by fluorescence resonance energy transfer (FRET). The regulation ability of pH can be controlled by the length and sequence of the triplex stem, and the wide pH regulation range may be helpful for the application of DNAzymes in biological medicine delivery systems.

中文翻译：

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pH值调控的RNA裂解DNAzyme的刺激响应策略。

RNA裂解DNA酶在DNA酶中具有重要作用，由于其对离子的依赖性，已被广泛用于生物传感器，DNA纳米机器中。然而，在构建通用但通用的RNA裂解DNA酶刺激反应策略方面仍然存在挑战。在本文中，通过巧妙设计发夹纳米结构，提出了一种刺激RNA裂解DNAzyme的刺激响应策略，其中发夹环中的DNAzyme（依赖Pb ^2+的DNAzyme作为模型）的活性通过使用三联阀杆作为“锁”。引入“关键” pH值后，在Pb ²⁺存在下，DNAzyme将被激活并使其底物片段化，伴随着通过荧光共振能量转移（FRET）猝灭的荧光的开启。pH的调节能力可以通过三链体茎的长度和序列来控制，宽的pH调节范围可能有助于DNA酶在生物药物递送系统中的应用。