基于上转换信标探针构建信号放大近红外激发荧光生物传感器用于microRNA检测.

In this work, a near-infrared light (NIR)-driven fluorescence biosensor is proposed based on the upconversion beacon probe and catalytic hairpin reaction (CHA) for the detection of microRNA. The target microRNA-21 (miRNA-21) can trigger the CHA reaction between the DNA hairpin H1 modified on magnetic beads (MBs) and the DNA hairpin H2 modified on upconversion nanoparticles (UCNPs), resulting in the introduction of UCNPs on the surface of MBs accompanied by the cyclic signal amplification. Through magnetic separation, the UCNPs fixed on MBs are separated and generate upconversion luminescence (UCL) under the excitation of 808 nm NIR, which shows the advantages of good luminescence stability and negligible photodamage. In this biosensor, the linear range of miRNA-21 is 0. 1 to 100 nmol/L with the detection limit of 11. 3 pmol/L. In addition, this fluorescence biosensor achieves the detection of miRNA-21 in serum samples, showing good practicability. [ABSTRACT FROM AUTHOR]