Fluorescent G-Quadruplex Nanowire-Enabled One-Pot Detection of Multiple Acute Myocardial Infarction-Related miRNAs

Acute myocardial infarction (AMI) is a deadly medical emergency with acute morbidity and high mortality, posing a considerable threat to human health and public safety. The early and accurate diagnosis of AMI is particularly important, as it benefits timely treatment of AMI patients, improves prognosis, and eventually reduces mortality. MicroRNAs (miRNAs) are superior biomarkers for AMI, and the joint testing of multiple AMI-related miRNAs provides more reliable results. Toward this goal, we herein develop a unique enzymatic cascade-reaction-powered fluorescence sensing platform for multiple AMI-related miRNAs, including miR-133a, miR-208b, miR-328, and miR-499a. The sensing system consists of tailor-made DNA primers with 3'-phosphorylated ends and two enzymes: duplex-specific nuclease (DSN) and terminal deoxynucleotidyl transferase (TdT). The utilization of bienzymes enables two-stage signal amplification, and the signal is reported by the production of G-quadruplex nanowires stained by thioflavin T (ThT). This method can effectively detect miR-133a, miR-208b, miR-328, and miR-499a with detection limits of 0.55, 65.7, 3.09, and 0.08 pM, respectively. It exhibits high selectivity and anti-interference capability. These miRNAs in human serum samples are also analyzed with satisfactory recovery rates. Receiver operating characteristic curve analysis revealed an area under the curve of 0.821 for the combination of these four miRNAs. In conclusion, this work may provide a highly efficient and clinically promising innovative miRNAs detection platform, with the potential to realize rapid and accurate diagnosis of AMI and facilitate timely intervention and treatment.