Calcium ion is a type of indispensable metal elements in biology, which participates in processes like maintaining the excitability of neuromuscular muscles. However, calcium content should be monitored in a safety range. Herein, a novel electrochemical method is developed for Ca assay by monitoring electrochemical response after DNAzyme catalyzed DNA hydrogel degradation. Pure DNA hydrogel is first built with three-way junction scaffolds and linkers containing Ca-dependent DNAzyme sequence. In the presence of target Ca, the substrates in linkers are cleaved and DNA hydrogel can be degraded gradually. The encapsulated electrochemical species thus facilely interact with the electrode, leading to the increase of electrochemical responses. This electrochemical method for Ca quantification is selective and sensitive, which also performs satisfactorily challenging biological samples like sweat and urine.

中文翻译：

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基于 DNAzyme 催化 DNA 水凝胶降解的 Ca2+ 电化学分析

钙离子是生物中不可缺少的金属元素，参与维持神经肌肉兴奋性等过程。然而，钙含量应控制在安全范围内。在此，通过监测 DNAzyme 催化 DNA 水凝胶降解后的电化学反应，开发了一种用于 Ca 测定的新型电化学方法。纯 DNA 水凝胶首先由三路连接支架和含有 Ca 依赖性 DNAzyme 序列的接头构建。在目标 Ca 存在的情况下，接头中的底物被裂解，DNA 水凝胶可以逐渐降解。因此，封装的电化学物质很容易与电极相互作用，导致电化学响应的增加。这种用于 Ca 定量的电化学方法具有选择性和灵敏性，对于汗液和尿液等具有挑战性的生物样品也具有令人满意的性能。