Magnetic covalent organic framework nanospheres-based miRNA biosensor for sensitive glioma detection

Sensitive detection and accurate diagnosis/prognosis of glioma remain urgent challenges. Herein, dispersed magnetic covalent organic framework nanospheres (MCOF) with uniformed Fe₃O₄ nano-assembly as cores and high-crystalline COF as shells were prepared by monomer-mediated in-situ interface growth strategy. Based on the unique interaction between MCOF and hairpin DNA, a fluorescent signal amplified miRNA biosensor was constructed. It could realize the sensitive detection of miRNA-182 in different matrixes, where the detection limit, linearity range and determination coefficient (R²) in real blood samples reached 20 fM, 0.1 pM-10 pM and 0.991, respectively. Also, it possessed good stability and precision as observed from the low intra-day/inter-day RSD and high extraction recovery. As a result, it could quantify miRNA-182 in serum of glioma patients, the concentration of which was significantly higher than that of healthy people and obviously decreased after surgery. Finally, a proof-of-concept capillary chip system using this biosensor was proposed to realize the visualized detection of miRNA-182 in microsample. These findings suggest a robust way for sensitive detection and accurate diagnosis/prognosis of glioma.