Li Dan, Zhang Xiao-Long, Chai Ya-Qin, Yuan Ruo
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P.R. China.
Anal Chem. 2023 Jan 17;95(2):1490-1497. doi: 10.1021/acs.analchem.2c04519. Epub 2023 Jan 3.
In this work, a high-efficiency controllable three-dimensional (3D) DNA nanomachine (CDNM) was reasonably developed by regulating the diameter of the core and the length of the DNAzyme cantilever, which acquired greater amplification efficiency and speedier walking rate than traditional 3D DNA nanomachines with gold nanoparticles as the cores and DNAzymes as the walking arms. Significantly, once the target miRNA-21 existed, a large number of silent DNAzymes on the CDNM could be activated by enzyme-free-target-recycling amplification (EFTRA) to achieve fast cleavage and walking on the biosensor surface under the interaction of Mg. Impressively, when the diameter of the core was 40 nm and the length of the DNAzyme cantilever was 5 nm (15 bp), the CDNM could complete the reaction process in 60 min that was at least twice shorter than those of conventional DNA nanomachines. Moreover, the designed electrochemical biosensor successfully detected target miRNA-21 at an ultrasensitive level with a wide response range (100 aM to 1 nM) and a low detection limit (33.1 aM). Therefore, the developed CDNM provides a new idea for exploring functional DNA nanomachines in the field of biosensing for applications.
在这项工作中，通过调节核心直径和脱氧核酶悬臂的长度，合理开发了一种高效可控的三维（3D）DNA纳米机器（CDNM），与以金纳米颗粒为核心、脱氧核酶为行走臂的传统3D DNA纳米机器相比，它具有更高的扩增效率和更快的行走速度。值得注意的是，一旦存在靶标miRNA-21，CDNM上的大量沉默脱氧核酶可通过无酶靶标循环扩增（EFTRA）被激活，以在镁的相互作用下在生物传感器表面实现快速切割和行走。令人印象深刻的是，当核心直径为40 nm且脱氧核酶悬臂长度为5 nm（15个碱基对）时，CDNM可在60分钟内完成反应过程，这比传统DNA纳米机器至少快两倍。此外，所设计的电化学生物传感器成功地在超灵敏水平检测到靶标miRNA-21，具有宽响应范围（100 aM至1 nM）和低检测限（33.1 aM）。因此，所开发的CDNM为在生物传感领域探索功能性DNA纳米机器提供了新的思路，可用于实际应用。
