Highly sensitive fluorescence multiplexed miRNAs biosensors for accurate clinically diagnosis lung cancer disease using LNA-modified DNA probe and DSN enzyme.

With the emergence of microRNAs as key biomarkers for disease diagnosis such as lung cancer, various techniques have been settled for their detection. However, these current methods require different amplification steps since numerous challenges for detecting circulating miRNAs are attributable to their intrinsic properties accounting for tiny sizes, high sequence similarity, and low abundance. Duplex specific nuclease (DSN)-based microRNA amplification has recently gained interest in biosensing applications thanks to its catalytic activity based on target recycling. In this context, we designed a highly selective, sensitive, and multiplexed fluorescence-based biosensor combining DSN enzyme and magnetic beads to detect three distinct microRNAs, including microRNA-21, microRNA-210, and microRNA-486-5p. By exploiting the above approach, we were able to detect as low as 98 aM, 120 aM, and 300 aM of mir-21, miR-210, and miR-486-5p, respectively. Furthermore, this recommended strategy displays a high selectivity toward an entirely matched target than the off-target. These results are ascribed to the potent DSN enzyme activity and to the locked nucleic acid (LNA)-modified DNA probe that boosted the hetero-duplex probe/target stability. Lastly, our proposed method was applied to detect microRNAs in the serum samples and displayed a high efficacy to discriminate between healthy controls and lung cancer patients. Furthermore, the analytical accuracy of the proposed strategy was validated with the computed tomography (CT) technique of the chest. Thus based on these findings, this strategy could open new directions for detecting microRNAs associated with several diseases.