A CHA amplifier assisted DNA logical circuits for accurate diagnosis of acute myocardial infarction

Developing sensitive and reliable strategies for the simultaneous detection of multiple miRNAs is crucial for the accurate diagnosis of acute myocardial infraction (AMI). Herein, we have rationally designed a signal amplifier-assisted DNA "AND" logic gate for simultaneously detecting three AMI-related miRNAs. To achieve amplified signal output, hairpins labeled with FAM and BHQ1 are employed, which remain in the signal-off state. Upon the input of all three targets, the "AND" logic gate is activated, resulting in the release of a trigger molecule. This trigger molecule then initiates the catalytic hairpin assembly (CHA) reaction, leading to amplified fluorescence signal enhancement. Notably, the system demonstrates excellent sensing performance in serum, exhibiting a wide detection range spanning from 0.05 to 20 nM and low limits of detection (31.34, 39.07, and 23.86 pM) for the three miRNAs. The AND-CHA system ensures that fluorescence signal output is obtained only when all three inputs are present simultaneously. It provides a direct result without the need for further signal analysis, thereby improving diagnostic accuracy and convenience.