DNA Tetrahedron-Confined Localized CHA for Rapid and Multiplex miRNA Sensing toward Live-Cell Imaging and Clinical Cancer Diagnostics

This is the authors' abstract. We don't add key points for this paper.

Achieving precise, multi-target profiling of intracellular microRNAs (miRNAs) is pivotal for cancer stratification but is hindered by the kinetic sluggishness and potential signal crosstalk of conventional diffusion-based probes. To overcome these barriers, we engineered a spatially segregated, dual-color logic gate anchored on a discrete DNA tetrahedron (DTN). Distinct from aggregation-based assays that rely on intermolecular assembly, this platform utilizes strict intramolecular nanoconfinement. By stoichiometrically positioning two orthogonal catalytic hairpin assembly (CHA) modules at a defined proximity of approximately 14.6 nm, we induce a 2.54 × 10 6 -fold surge in effective local molarity. This design drives ultrafast strand displacement kinetics while maintaining the nanostructure in a monodispersed state, which is critical for efficient cellular uptake. The resultant DTN-confined localized CHA (DTN-LCHA) system operates as a leakage-free “nanolab-on-a-particle”, enabling carrier-independent cytosolic delivery via caveolae-mediated endocytosis. Consequently, the system allows for the simultaneous, ratiometric imaging of miR-21 and miR-31, successfully discriminating breast cancer subtypes and validating clinical serum samples with high fidelity. This work presents a generalizable paradigm for engineering non-interfering, high-speed molecular circuits for accurate disease phenotyping.