传统的微小RNA（miRNA）的电化学检测遇到了灵敏度低和动态范围固定的问题。在这里，我们报道了一种DNA瓦片和侵袭堆叠引物辅助CRISPR-Cas12a多重扩增策略，用于构建一个熵控制的可调灵敏度和动态范围的电化学生物传感器，用于检测miRNA。为了扩大信号，设计了CRISPR-Cas12a系统的级联扩增以及侵袭堆叠引物信号扩增（ISPSA），用于检测微量的miRNA-31（miR-31）。靶向miR-31能够激活ISPSA，并产生大量的DNA，触发连接亚甲基蓝标记的DNA瓦片和DNA四面体的单链连接探针（LP）的剪切，从而在电极上形成一个Y形DNA支架。基于电流的下降，可以准确高效地检测miR-31。令人印象深刻的是，通过改变LP的环长度，可以在保持焓贡献恒定的同时，精确调节熵贡献。这种策略显示了对miRNA的检测限量的可调节性，从0.31 fM到0.56 pM，以及约2200倍到约270,000倍的动态范围。此外，它在鉴定miR-31高表达的癌细胞方面展示了满意的结果。我们的策略拓宽了传统的电化学生物传感的应用，并提供了一种可调节的策略，用于检测浓度不同的miRNA。

Conventional electrochemical detection of microRNA (miRNA) encounters issues of poor sensitivity and fixed dynamic range. Here, we report a DNA tile and invading stacking primer-assisted CRISPR-Cas12a multiple amplification strategy to construct an entropy-controlled electrochemical biosensor for the detection of miRNA with tunable sensitivity and dynamic range. To amplify the signal, a cascade amplification of the CRISPR-Cas12a system along with invading stacking primer signal amplification (ISPSA) was designed to detect trace amounts of miRNA-31 (miR-31). The target miR-31 could activate ISPSA and produce numerous DNAs, triggering the cleavage of the single-stranded linker probe (LP) that connects a methylene blue-labeled DNA tile with a DNA tetrahedron to form a Y-shaped DNA scaffold on the electrode. Based on the decrease of current, miR-31 can be accurately and efficiently detected. Impressively, by changing the loop length of the LP, it is possible to finely tune the entropic contribution while keeping the enthalpic contribution constant. This strategy has shown a tunable limit of detection for miRNA from 0.31 fM to 0.56 pM, as well as a dynamic range from ∼2200-fold to ∼270,000-fold. Moreover, it demonstrated satisfactory results in identifying cancer cells with a high expression of miR-31. Our strategy broadens the application of conventional electrochemical biosensing and provides a tunable strategy for detecting miRNAs at varying concentrations.