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.
Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
Anal Chem. 2021 Oct 19;93(41):13952-13959. doi: 10.1021/acs.analchem.1c03215. Epub 2021 Oct 6.
Herein, we designed a dual 3D DNA nanomachine (DDNM)-mediated catalytic hairpin assembly (DDNM-CHA) to construct an electrochemical biosensor for ultrasensitive detection of miRNA, which possesses quite a faster reaction rate and much higher amplification efficiency than those of traditional catalytic hairpin assembly (CHA). Impressively, since the DDNM skillfully increases the local concentration of reactants and decreases the steric hindrance of substrates simultaneously, the DDNM-CHA could be endowed with higher collision efficiency and more effective reaction compared with traditional CHA, resulting in a hyper conversion efficiency up to 2.78 × 10 only in 25 min. This way, the developed DDNM-CHA could easily conquer the main predicaments: long reaction time and low efficiency. As a proof of the concept, we adopt the gold nanoparticles (AuNPs) and the magnetic nanoparticle (FeO) as the kernel of DNM-A and DNM-B, respectively, and harness the magnetic electrode to directly adsorb the products H1-H2/FeO for constructing an immobilization-free biosensor for high-speed and ultrasensitive detection of miRNA with a detection limit of 0.14 fM. As a result, the DDNM-CHA we developed carves out a new insight to design a functional DNA nanomachine and evolve the analysis method for practical amplification in the sensing area and promotes the deeper exploration of the nucleic acid signal amplification strategy and DNA nanobiotechnology.
在这里，我们设计了一种双 3D DNA 纳米机器（DDNM）介导的催化发夹组装（DDNM-CHA），用于构建电化学生物传感器，以超灵敏地检测 miRNA，其反应速率比传统的催化发夹组装（CHA）快得多，放大效率也高得多。令人印象深刻的是，由于 DDNM 巧妙地同时增加了反应物的局部浓度并降低了底物的空间位阻，因此与传统的 CHA 相比，DDNM-CHA 可以具有更高的碰撞效率和更有效的反应，从而达到高达 2.78×10 的超转化率，仅需 25 分钟。通过这种方式，开发的 DDNM-CHA 可以轻松克服主要困境：反应时间长和效率低。作为概念验证，我们分别将金纳米粒子（AuNPs）和磁性纳米粒子（FeO）用作 DNM-A 和 DNM-B 的核心，并利用磁性电极直接吸附产物 H1-H2/FeO，构建用于超灵敏检测 miRNA 的无固定化生物传感器，检测限低至 0.14 fM。结果，我们开发的 DDNM-CHA 为设计功能性 DNA 纳米机器开辟了新的思路，并为传感领域的实际放大分析方法提供了新的思路，促进了对核酸信号放大策略和 DNA 纳米生物技术的更深入探索。
