A simple microRNA (miRNA) aptasensor has been developed combining the conformational switch of a streptavidin aptamer and isothermal strand displacement amplification. In the presence of its target miRNA, the allosteric molecular beacon (aMB) probe immobilized on the plate can be 'switched on' and release the streptavidin aptamer. At the same time, Klenow fragment (3'→5' exo-) is utilized to initiate DNA-strand displacement, which starts the target recycling process. Based on the aptamer' high binding affinity and subsequent catalytic chemiluminescence (CL) detection, this CL strategy is highly specific in distinguishing mature miRNAs in same family. It exhibits a dynamic range of four orders of magnitude with a detection limit of 50 fM, and shows great potential for miRNA-related clinical practices and biochemical research.

中文翻译：

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基于构象开关的适体传感器，用于化学发光检测微小RNA。

已经开发了一种简单的microRNA（miRNA）适体传感器，结合了链霉亲和素适体的构象转换和等温链置换扩增。在其靶标miRNA存在下，固定在板上的变构分子信标（aMB）探针可以“打开”并释放链霉亲和素适体。同时，利用Klenow片段（3'→5'exo-）引发DNA链置换，从而启动了目标回收过程。基于适体的高结合亲和力和随后的催化化学发光（CL）检测，这种CL策略在区分同一家族中的成熟miRNA方面具有高度特异性。它的动态范围为四个数量级，检测极限为50 fM，在miRNA相关的临床实践和生化研究中显示出巨大的潜力。