(Eu-MOF)-derived Smart luminescent sensing for Ultrasensitive on-site detection of MiR-892b.

MicroRNAs (miRNAs) are important biomacromolecules used as biomarkers for the diagnosis of several diseases. However, current detection strategies are limited by expensive equipment and complicated procedures. Here, we develop a portable, sensitive, and stable (Eu-MOF)-based sensing platform to detect miRNA via smartphone. The Eu-MOF absorbs the carboxyfluorescein (FAM)-tagged probe DNA (pDNA) to generate hybrid pDNA@Eu-MOF, which can efficiently quench the fluorescence of FAM through a photoinduced electron transfer (PET) process. When integrated with a smartphone, the nonemissive pDNA@ Eu-MOF hybrid could be utilized as a portable and sensitive platform to sense miRNA (miR-892b) with a detection limit of 0.32 pM, which could be even distinguished by the naked eye. Moreover, this system demonstrates high selectivity for identifying miRNA family members with single-base mismatches. Furthermore, the expression levels of miRNA in cancer cell samples could be analyzed accurately. Therefore, the proposed method offers a promising guideline for the design of MOF-based sensing strategies and expands their potential applications for diagnostic purposes.