An Au-Se bond-based fluorescent nanoprobe for thermophoretic aggregation imaging of exosomal miRNAs

Exosomal microRNAs (miRNAs) have recently gained prominence as promising biomarkers for non-invasive lung cancer screening. In this study, we innovatively developed an innovative fluorescent nanoprobe based on stable Au-Se bonds to detect lung cancer-associated miRNAs in exosomes. This nanoprobe integrates gold nanoparticles with selenated DNA molecular beacons (MBs) conjugated via 1,4-phenyldiisothiocyanate (PDITC). It demonstrates exceptional stability in high-thiol environments, making it ideal for high-fidelity imaging and biomarker detection in biological settings. By integrating molecular beacons that specifically recognize and bind to target exosomal miRNAs, the nanoprobe enables precise detection. Thermophoretic aggregation imaging of exosomes was achieved using confocal fluorescence microscopy with 1064 nm laser irradiation. Our findings demonstrate that this nanoprobe efficiently identifies lung cancer-related miRNAs in exosomes, providing a promising candidate for early lung cancer detection in clinical applications.