MicroRNA-21 (miR-21) has been widely investigated as important biomarkers for cancer diagnosis and treatment. Herein, a highly sensitive nonenzymatic electrochemical biosensor based on Pd@metal-organic frameworks (Pd@UiO-66) and target-catalytic hairpin assembly (CHA) with target recycling approach has been proposed for the detection of miR-21. The proposed biosensor integrates the efficient CHA strategy and excellent electrocatalytic performance of Pd@UiO-66 nanocomposites. The concentration of miRNA-21 is related to the amount of the adsorbed electrocatalyst, leading to the different electrochemical signals for readout towards paracetamol (AP). This biosensor shows a low limit of detection of 0.713 fM with the dynamic range of 20 fM -600 pM under the optimal experimental conditions, providing a powerful platform for detecting miR-21. Furthermore, the designed biochemical self-assembly strategy of this electrochemical biosensor is promising candidate for potential applications in the analysis of other important genetic biomarkers for early diagnosis of cancers.

中文翻译：

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基于靶催化发夹组装和 Pd@UiO-66 的无酶电化学生物传感器用于超灵敏检测 microRNA-21

MicroRNA-21 (miR-21) 作为癌症诊断和治疗的重要生物标志物已被广泛研究。在此，提出了一种基于 Pd@metal-organic framework (Pd@UiO-66) 和具有目标回收方法的目标催化发夹组装 (CHA) 的高灵敏度非酶电化学生物传感器，用于检测 miR-21。所提出的生物传感器集成了 Pd@UiO-66 纳米复合材料的高效 CHA 策略和优异的电催化性能。miRNA-21 的浓度与吸附的电催化剂的量有关，导致读取对乙酰氨基酚 (AP) 的不同电化学信号。该生物传感器在最佳实验条件下的检测下限为0.713 fM，动态范围为20 fM -600 pM，为检测miR-21提供了强大的平台。此外，