Herein, a dual-signal amplification electrochemical sensing has been proposed for the ultrasensitive detection of uranyl ions (UO₂²⁺) by integration of gold nanoparticles (AuNPs) and hybridization chain reaction (HCR)-assisted synthesis of silver nanoclusters (AgNCs). In this sensing platform, AuNPs are used as an ideal signal amplification carrier, aiming at increasing the loads of UO₂²⁺-specific DNAzyme on the gold electrode. In the presence of UO₂²⁺, UO₂²⁺-specific DNAzyme can be activated, leading to the cleavage of substrate strands (S-DNA). Then, HCR is triggered to produce long dsDNA through hybridization the probe with the ssDNA on the electrode surface. As a result, an amplified electrochemical response can be detected by inserting a large amount of AgNCs generated in situ using dsDNA as template. Featured with amplification efficiency, good specificity and high sensitivity, the strategy could quantitatively detect UO₂²⁺ down to 6.2 pM with a linear calibration range from 20 pM to 5000 pM. The proposed sensing platform has been also successfully demonstrated the practical application of detecting UO₂²⁺, indicating that the developed method has the potential applications and can open up a new avenue for highly sensitive detection of UO₂²⁺ in environmental monitoring.

在此，通过金纳米粒子 (AuNPs) 的整合和杂化链反应 (HCR) 辅助合成银纳米团簇 (AgNCs)，提出了一种双信号放大电化学传感用于铀酰离子 (UO ₂ ²⁺ )的超灵敏检测。在该传感平台中，AuNPs 被用作理想的信号放大载体，旨在增加金电极上UO ₂ ²⁺特异性 DNAzyme的负载。在存在 UO ₂ ^{2+ 时}，UO ₂ ²⁺-特异性 DNAzyme 可以被激活，导致底物链 (S-DNA) 的裂解。然后，通过将探针与电极表面上的 ssDNA 杂交，触发 HCR 以产生长 dsDNA。因此，可以通过插入大量使用 dsDNA 作为模板原位生成的 AgNCs 来检测放大的电化学响应。该策略具有扩增效率、特异性好、灵敏度高等特点，可定量检测低至6.2 pM的UO ₂ ²⁺，线性校准范围为20 pM至5000 pM。所提出的传感平台也成功地展示了检测 UO ₂ ²⁺的实际应用，表明该方法具有潜在的应用价值，可以为环境监测中UO ₂ ^{2+ 的}高灵敏度检测开辟一条新途径。