A catalytic hairpin amplification platform triggered by near-infrared light and logic assembly for sensitive detection of microRNAs.

Research has shown that miRNA-21 levels increase during vascular aging, making it a promising biomarker for vascular aging. Therefore, developing sensitive miRNA-21 detection techniques is crucial for early diagnosis, therapeutic intervention, and prognosis assessment of vascular aging. This work developed an enzyme-free fluorescence sensing platform based on upconversion nanoparticles (UCNPs) and a catalytic hairpin assembly (CHA), which uses 808 nm light-controlled switches and fluorescence resonance energy transfer (FRET) signal regulation for highly sensitive and specific quantification of miRNA-21. First, the loaded DNA hairpins and the UCNPs were released under weakly acidic conditions due to the disintegration of the organic framework material (ZIF-8). Under 808 nm irradiation, when the analyte miRNA-21 is present, the DNA hairpin (H1) undergoes specific unwinding, triggering CHA, leading to signal recovery of the fluorescent group on another DNA hairpin (H2) and quantitative detection of miRNA-21. The degree of fluorescence restoration of the sensor exhibited a good linear correlation with the miRNA-21 concentration in the range of 0.5-25 nM, and the limit of detection reached 0.128 nM. Moreover, this method exhibits excellent analytical performance in the detection of serum samples, with spiked recovery rates ranging from 98.2% to 102.8%. These data demonstrate that the light-controlled sensing platform has significant merits, such as high detection sensitivity, strong specificity, and minimal background interference, providing a reliable method for the rapid quantification of miRNA-21 in complex matrices.