DNA Nanotechnology‐Engineered Supramolecular Hydrogel Biosensor for Cancer Diagnosis via Extracellular Vesicles

Cancer‐associated extracellular vesicles (EVs) are promising as liquid biopsy biomarkers for early cancer diagnosis to reduce cancer‐related mortality, yet their clinical utility remains hampered by cumbersome workflows and insufficient diagnostic accuracy. Herein, these limitations are addressed with a DNA nanotechnology‐engineered supramolecular hydrogel biosensor that integrates EV recognition, isolation, enrichment, and detection into a rapid assay (30 min vs hours for conventional methods). The biosensor leverages a sequence‐programmable DNA hydrogel matrix, constructed via gene‐like precision in supramolecular assembly, to spatially organize polyvalent aptamers for efficient EV capture. Crucially, the cancer‐associated miRNA‐21 and membrane protein epithelial cell adhesion molecule (EpCAM) synergistically trigger cascaded assembly of DNA probes, generating three‐color fluorescence signals for semi‐quantitative dual‐marker analysis. Remarkably, the biosensor demonstrates exceptional correlation with gold‐standard techniques methods, with Pearson's coefficients of 0.987 for miRNA‐21 and 0.999 for EpCAM. The dual‐marker approach minimizes false negatives and achieves 100% accuracy in distinguishing breast cancer patients from healthy donors in serum samples. By unifying molecular recognition, signal amplification, and multiplexed detection in a single material platform, this work advances EV‐based liquid biopsy through a chemistry‐driven design, offering a scalable, rapid, and ultrasensitive tool for early cancer diagnosis.