{Reference Type}: Journal Article {Title}: Fluorescent DNA tetrahedral probe with catalytic hairpin self-assembly reaction for imaging of miR-21 and miR-155 in living cells. {Author}: Wang S;Guang J;Gao Y;Fan B;Liang Y;Pan J;Li L;Meng W;Hu F; {Journal}: Mikrochim Acta {Volume}: 191 {Issue}: 8 {Year}: 2024 07 11 {Factor}: 6.408 {DOI}: 10.1007/s00604-024-06529-4 {Abstract}: A CHA-based fluorescent DNA tetrahedral probe (FDTp) has been designed to detect the microRNAs miR-21 and miR-155 sensitively and specifically in living cells. The design consisted of functional elements (H1, H2, and Protector) connected to a DNA tetrahedron modified with two pairs of fluorophores and quenching groups. In the presence of miR-21, the chain displacement effect was triggered and Cy3 fluorescence was emitted. In the presence of miR-155, the signal of the catalytic hairpin assembly (CHA) between H1 and H2 on FDTp was amplified, making the fluorescence of FAM sensitive to miR-155. Using this method, the detection limit for miR-155 was 5 pM. The FDTp successfully imaged miR-21 and miR-155 in living cells and distinguished a variety of cell lines based on their expression levels of miR-21 and miR-155. The detection and imaging of dual targets in this design ensured the accuracy of tumor diagnosis and provided a new method for early tumor diagnosis.