MOF-Powered MicroRNA Catch for Ultrasensitive Breast-Cancer Screening

MicroRNAs (miRNAs) are key regulators of disease-associated signaling pathways and serve as critical biomarkers for cancer. However, their accurate and reliable quantification in complex biofluids such as serum remains challenging because of their ultralow abundance and matrix interference, which severely limit their clinical and point-of-care testing (POCT) utility. To overcome this hurdle, we developed an electrochemical biosensor that integrates a UiO-66-NH₂ enrichment strategy for the specific and rapid detection of miRNAs and validated it in clinical serum samples. UiO-66-NH₂ was used to adsorb Texas Red-labeled miRNA aptamers, generating a high-density capture material (Apt-UiO-66-NH₂) that selectively enriched target miRNAs. After enrichment, sodium tripolyphosphate (STPP) was employed to release aptamers─both those bound to miRNAs and those remaining unbound─from the MOF. The released single-stranded aptamers were then quantified with an electrochemical biosensor fabricated on a screen-printed electrode (SPE), allowing the determination of the target miRNA. The assay accomplishes rapid (<45 min) and sensitive detection of miR-21, miR-155, and miR-96 and can distinguish breast-cancer patients from postoperative recovery subjects. These results demonstrate the potential of this biosensor for real-time health monitoring and POCT miRNA analysis, particularly for breast-cancer diagnosis.