Yu Chenhong, Yang Xu, Yang Bei, Li Weiying, Wang Jianbang, Liu Huajie
School of Chemical Science and Engineering, Shanghai Research Institute for Intelligent Autonomous Systems, Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Tongji University, Shanghai, 200092, China.
College of Environmental Science and Engineering, Shanghai Institute of Pollution Control and Ecological Security, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, China.
Biosens Bioelectron. 2025 Nov 1;287:117707. doi: 10.1016/j.bios.2025.117707. Epub 2025 Jun 18.
Detecting biomolecules, particularly disease markers, is an important issue for practical diagnosis and clinical therapies. Herein, we proposed an all-DNA hydrogel-based electrochemical impedance sensing platform for ultrasensitive detection of miRNA-21 by synergistic integration of dual amplification circuits: catalytic hairpin assembly (CHA) and clamped hybridization chain reaction (C-HCR). A hairpin DNA complementary to miRNA-21 was designed to initiate CHA, resulting in the self-assembly of dsDNA products upon target addition. This process generates numerous trigger sequences that activate the subsequent C-HCR to form DNA hydrogels on the electrode surface. The insulating DNA hydrogel film significantly enhances impedance responses, allowing us to establish a highly sensitive impedimetric biosensor for miRNA-21 analysis. Our dual signal amplification strategy using DNA hydrogels as the amplification element showed higher electrochemical response, broader dynamic range (10 aM ∼ 10 nM), and lower detection limit (6.5 aM). In addition, this electrochemical impedimetric biosensor with excellent selectivity, non-destructivity, and label-free feature is suitable for practical analytes, highlighting its great potential in clinical diagnostics.
检测生物分子，尤其是疾病标志物，对于实际诊断和临床治疗而言是一个重要问题。在此，我们提出了一种基于全DNA水凝胶的电化学阻抗传感平台，用于通过双扩增电路（催化发夹组装（CHA）和钳位杂交链式反应（C-HCR））的协同整合来超灵敏检测miRNA-21。设计了与miRNA-21互补的发夹DNA来启动CHA，在加入靶标后导致双链DNA产物的自组装。该过程产生大量触发序列，激活随后的C-HCR以在电极表面形成DNA水凝胶。绝缘的DNA水凝胶膜显著增强阻抗响应，使我们能够建立一种用于miRNA-21分析的高灵敏阻抗生物传感器。我们使用DNA水凝胶作为扩增元件的双信号放大策略显示出更高的电化学响应、更宽的动态范围（10 aM ∼ 10 nM）和更低的检测限（6.5 aM）。此外，这种具有优异选择性、非破坏性和无标记特征的电化学阻抗生物传感器适用于实际分析物，突出了其在临床诊断中的巨大潜力。
