An intramolecular DNAzyme-based amplification for miRNA analysis with improving reaction kinetics and high sensitivity

作者：Huang, Ting; Chen, Guixun; Liu, Birong; Yang, Zizhong; Huang, Yuanwei; Xie, Baoping; Li, Min-Min; Chen, Jin-Xiang^*; Chen, Jun; Dai, Zong

来源：Talanta, 2022, 239: 123137.

DOI：10.1016/j.talanta.2021.123137

• miRNA
• DNAzyme
• Fluorescence
• Ultrasensitive determination
• Isothermal amplification reaction

Sensitive, specific and rapid methods for detecting microRNAs (miRNAs) play critical roles in disease diagnosis and therapy. Enzyme-free amplification techniques based on DNAzyme assembly have recently been developed for the highly specific miRNA analysis. However, traditional DNAzyme-based assembly (free DNAzyme) am-plifiers is mainly dependent on the target-induced split DNAzyme fragments to assemble into activated DNAzyme structures, which have made a compromise between the sensitivity and specificity due to the random diffusion of dissociative probes in a bulk solution with poor kinetics. Herein, based on a rationally designed DNA probe, we developed an intramolecular DNAzyme assembly (intra-DNAzyme) method to overcome these challenges. The miR-373 is used as model analyte for our current proof-of-concept experiments. Compared with the free-DNAzyme method, our method showed significantly improved analytical performance in terms of dynamic range, assay sensitivity and speed. This method can detect miR-373 specifically with a detection limit as low as 4.3 fM, which is about 83.7 times lower than the previous free-DNAzyme method. This intra-DNAzyme strategy would be of great value in both basic research and clinical diagnosis.

• 单位
  中山大学; 1; 南方医科大学