Key Laboratory of Analytical Science and Technology of Hebei Province, College of Chemistry and Materials Science, Hebei University, Baoding 071002, P. R. China.
Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
Anal Chem. 2024 Sep 10;96(36):14471-14479. doi: 10.1021/acs.analchem.4c02565. Epub 2024 Aug 26.
The spatial constraints imposed by the DNA structure have significant implications for the walking efficiency of three-dimensional DNA walkers. However, accurately quantifying and manipulating steric hindrance remains a challenging task. This study presents a steric hindrance-controlled DNA walker utilizing an enzymatic strand displacement amplification (ESDA) strategy for detecting microRNA-21 (miR-21) with tunable dynamic range and sensitivity. The steric hindrance of the DNA walker was precisely manipulated by varying the length of empty bases from 6.5 Å to 27.4 Å at the end of the track strand and adjusting the volumetric dimensions of the hairpin structure from 9.13 nm to 26.2 nm at the terminus of the single-foot DNA walking strand. This method demonstrated a tunable limit of detection for miR-21 ranging from 3.6 aM to 35.6 nM, along with a dynamic range from ∼100-fold to ∼166 000-fold. Impressively, it exhibited successful identification of cancer cells and clinical serum samples with high miR-21 expression. The proposed novel strategy not only enables tunable detection of miRNA through the regulation of steric hindrance but also achieves accurate and quantitative analysis of the steric hindrance effect, promising broader applications in personalized medicine, early disease detection, and drug development.
DNA 结构所施加的空间限制对三维 DNA walker 的行走效率有重大影响。然而，准确地量化和操纵空间位阻仍然是一项具有挑战性的任务。本研究提出了一种利用酶促链置换扩增（ESDA）策略的空间位阻控制 DNA walker，用于检测 microRNA-21（miR-21），具有可调的动态范围和灵敏度。通过改变轨道链末端的空碱基长度（从 6.5 Å 到 27.4 Å），以及调整单足 DNA 行走链末端发夹结构的体积尺寸（从 9.13 nm 到 26.2 nm），精确地操纵 DNA walker 的空间位阻。该方法对 miR-21 的检测限具有可调性，范围从 3.6 aM 到 35.6 nM，动态范围从约 100 倍到约 166 000 倍。令人印象深刻的是，它成功地识别了具有高 miR-21 表达的癌细胞和临床血清样本。所提出的新策略不仅能够通过调节空间位阻来实现 miRNA 的可调检测，而且还能够实现对空间位阻效应的准确和定量分析，有望在个性化医疗、早期疾病检测和药物开发等领域得到更广泛的应用。
