Dual‐Functional Nanoconfined Metal‐Organic Frameworks with Aggregation‐Induced Electrochemiluminescence Coupled with DNAzyme Motor for Ultrasensitive miRNA‐21 Biosensing

Simultaneously overcoming aggregation‐induced quenching and sluggish interfacial kinetics remains a pivotal challenge in electrochemiluminescence. Herein, we have successfully synthesized dual‐functional nanoconfined metal–organic frameworks encapsulating Pt‐A‐COOH complexes (Pt@UiO‐67 MOFs) as electrochemiluminescence emitters and co‐reaction accelerators by a ligand‐similarity‐driven doping strategy. The dual‐functional Pt@UiO‐67 MOFs unlocked aggregation‐induced electrochemiluminescence and expedited interfacial reaction kinetics by spatial nanoconfinement, the electrochemiluminescence efficiency of which was ca . 5.4‐fold higher than that of the Pt‐A‐COOH as co‐reactant to catalyze the decomposition of S 2 O 8 2− . Density functional theory calculations and electrochemical electron paramagnetic resonance measurements indicated that the nanoconfinement structure reduced the activation energy barrier for the reduction of S 2 O 8 2− , thereby optimizing the kinetics of SO 4 •− (0.92 eV) and OH • (0.63 eV) radical generation. Based on the Pt@UiO‐67 MOFs and DNAzyme motor, the ultrasensitive biosensor has been successfully constructed and had wide linear range (from ∼10 aM to ∼10 nM) and an ultralow detection limit of ∼4.1 aM. In the preliminary proof‐of‐concept evaluation using acute kidney injury clinical samples, the assay results had excellent concordance with those of quantitative reverse transcription polymerase chain reaction. This work provides a paradigm integrating supramolecular engineering with DNA nanotechnology, which paves the way for sensitive biodetection and preliminary clinical screening.