The accurate and rapid analysis of heavy metal ions is significant for food safety and human health. In this work, a dual-palindrome chained assembly (dual-PCA) was rationally designed to form copper ion (Cu²⁺)-responsive palindromic DNAzyme wire (P-DNAzyme-W) transducers based on the inverted reading of palindromes. Structurally, P-DNAzyme-W is composed of numerous intermolecular paired dual-palindrome DNAzyme monomers. In the absence of Cu²⁺, the background fluorescence of the P-DNAzyme-W transducer was strongly quenched because of palindrome-induced co-quenching effects. Upon introduction of Cu²⁺ to form catalytic cores for the cleavage of the substrate strand into two parts, the sensing system exhibits strong fluorescence recovery within 25 min. These features allow the sensing system to exhibit a high signal-to-noise ratio to sensitized detect Cu²⁺ in one step but maximally maintain the simplicity of common DNAzyme monomers. Moreover, the sensing system possesses a good anti-matrix effect for sensitized detection of Cu²⁺ from lake water and tap water, suggesting promising potential in determining the level of Cu²⁺ in aquatic environments. We expect our research to provide an avenue to customize functional nucleic acids for heavy metal ion detection in the fields of food safety analysis, clinical diagnosis, and environmental monitoring.

重金属离子的准确快速分析对食品安全和人体健康具有重要意义。在这项工作中，基于回文的倒读，合理设计了双回文链式组件（dual-PCA）以形成铜离子（Cu ²⁺）响应的回文DNAzyme线（P-DNAzyme-W）传感器。在结构上，P-DNAzyme-W 由许多分子间配对的双回文 DNAzyme 单体组成。在没有Cu ²⁺的情况下，由于回文诱导的共猝灭效应，P-DNAzyme-W 传感器的背景荧光被强烈猝灭。引入Cu ²⁺为了形成将底物链切割成两部分的催化核心，传感系统在 25 分钟内表现出强烈的荧光恢复。这些特性使传感系统能够表现出高信噪比，以一步敏化检测 Cu ^{2+ ，但最大限度地保持常见 DNAzyme 单体的简单性。}此外，该传感系统对湖水和自来水中Cu ²⁺的敏化检测具有良好的抗基质效应，在测定水环境中Cu ^{2+水平方面具有广阔的应用前景。}我们希望我们的研究能够为食品安全分析、临床诊断和环境监测领域的重金属离子检测提供定制功能性核酸的途径。