Proximity ligation initiated DNAzyme-powered catalytic hairpin assembly for sensitive and accurate microRNA analysis

MicroRNAs (miRNAs) play a significant role in regulating diverse physiological processes, and are regarded as novel diagnostic biomarkers. However, the sensitive and reliable miRNA detection remains a huge challenge. Herein, we propose a proximity ligated initiated magnesium ion (Mg2+)-dependent DNAzyme-powered signal cascade for sensitive, accurate and reliable detection of miRNAs. Three signal amplification processes are involved in this approach, including the target miRNA recycle, DNAzyme powered substrate cleavage, and catalytic hairpin reaction (CHA). Based on this, the approach shows a low limit of detection of 523 aM and a wide detection range of 7 orders of magnitudes, which is comparable or superior to most of the former miRNA detection methods. In addition, the approach also possesses a high selectivity to target miRNA, suggesting a potential promising future of the approach for rapid detection of miRNAs in the application of developing novel tools for skin cancer diagnosis, and recovery evaluation.