Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573, Japan.
ACS Appl Mater Interfaces. 2021 Aug 4;13(30):35533-35544. doi: 10.1021/acsami.1c09631. Epub 2021 Jul 21.
Accelerated DNA hybridization chain reactions (HCRs) using DNA origami as a scaffold have received considerable attention in dynamic DNA nanotechnology. However, tailor-made designs are essential for DNA origami scaffolds, hampering the practical application of accelerated HCRs. Here, we constructed the semilocalized HCR and localized HCR systems using magnetic beads (MBs) as a simple scaffold to explore them for the enzyme-free miR-21 detection. The semilocalized HCR system relied on free diffusing one hairpin DNA and MBs immobilized with another hairpin DNA, and the localized HCR system relied on MBs coimmobilized with two hairpin DNAs. We demonstrated that the DNA density on MBs plays a critical role in HCR kinetics and limit of detection (LOD). Among semilocalized HCR systems, MBs with a medium DNA density showed a faster HCR and lower LOD (10 pM) than the diffusive (conventional) HCR system (LOD: 86 pM). In contrast, the HCR further accelerated for the localized HCR systems as the DNA density increased. The localized HCR system with the highest DNA density showed the fastest HCR and the lowest LOD (533 fM). These findings are of great importance for the rational design of accelerated HCRs using simple scaffolds for practical applications.
使用 DNA 折纸作为支架的加速 DNA 杂交链式反应 (HCR) 在动态 DNA 纳米技术中受到了广泛关注。然而，DNA 折纸支架需要定制设计，这阻碍了加速 HCR 的实际应用。在这里，我们使用磁珠 (MBs) 作为简单支架构建了半局部化 HCR 和本地化 HCR 系统，以探索它们在无酶 miR-21 检测中的应用。半局部化 HCR 系统依赖于自由扩散的一个发夹 DNA 和固定在 MBs 上的另一个发夹 DNA，而本地化 HCR 系统依赖于共固定在两个发夹 DNA 上的 MBs。我们证明了 MBs 上的 DNA 密度在 HCR 动力学和检测限 (LOD) 中起着关键作用。在半局部化 HCR 系统中，具有中等 DNA 密度的 MBs 表现出比扩散 (常规) HCR 系统更快的 HCR 和更低的 LOD(10 pM)(LOD:86 pM)。相比之下，随着 DNA 密度的增加，本地化 HCR 系统的 HCR 进一步加速。具有最高 DNA 密度的本地化 HCR 系统表现出最快的 HCR 和最低的 LOD(533 fM)。这些发现对于使用简单支架进行实际应用的加速 HCR 的合理设计具有重要意义。
