采用催化发夹组装混合链式反应（CHA-HCR）构建了基于双扩增核酸模式和生物催化银沉积的电化学生物传感器。通过线性扫描伏安法 (LSV) 对电极上银的电化学检测可用于定量测量 miR-205-5p，因为沉积在电极上的银量与靶核酸成正比。目前的响应值与 0.1 pM 至 10 μM 范围内的 miR-205-5p 浓度对数表现出很强的线性关系，检测限为 28 fM。 qRT-PCR 和电化学生物传感器技术的结果发现了一致的趋势，分别用于测定从细胞中回收的总 RNA。此外，构建的传感器用于评估各种细胞计数的 miR-205-5p，结果证明了所提出策略的出色分析效率。人血清样品中的回收率为 97.85% 至 115.3%，RSD 为 2.251% 至 4.869%。我们的用于 miR-205-5p 检测的电化学生物传感器表现出良好的特异性、高灵敏度、重复性和稳定性。它是临床环境中用于肿瘤诊断和肿瘤类型识别的潜在有用的传感平台。© 2024。作者获得 Springer-Verlag GmbH Austria（Springer Nature 旗下公司）的独家许可。

An electrochemical biosensor based on dual-amplified nucleic acid mode and biocatalytic silver deposition was constructed using catalytic hairpin assembly-hybrid chain reaction (CHA-HCR). The electrochemical detection of silver on the electrode by linear sweep voltammetry (LSV) can be utilized to quantitatively measure miR-205-5p since the amount of silver deposited on the electrode is proportional to the target nucleic acid. The current response values exhibit strong linearity with the logarithm of miR-205-5p concentrations ranging from 0.1 pM to 10 μM, and the detection limit is 28 fM. A consistent trend was found in the results of the qRT-PCR and electrochemical biosensor techniques, which were employed to determine the total RNA recovered from cells, respectively. Moreover, the constructed sensor was used to assess miR-205-5p on various cell counts, and the outcomes demonstrated the excellent analytical efficiency of the proposed strategy. The recoveries ranged from 97.85% to 115.3% with RSDs of 2.251% to 4.869% in human serum samples. Our electrochemical biosensor for miR-205-5p detection exhibits good specificity, high sensitivity, repeatability, and stability. It is a potentially useful sensing platform for tumor diagnosis and tumor type identification in clinical settings.© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.