Controlled synthesis of zinc-metal organic framework microflower with high efficiency electrochemiluminescence for miR-21 detection

In this study, as the self-enhanced electrochemiluminescence (ECL) emitter, the dual ligand metal-organic framework microflower was successfully synthesized via a facile one-pot method by integrating 9,10-di(pcarboxyphenyl) anthracene (DPA) ligand and N, N-Diethylethylenediamine (DEAEA) ligand into zinc ions metal node, denoted as Zn-DPA/DEAEA (d-MOF). The DPA ligand was a typical ECL luminophore. The DEAEA ligand not only could be used as an effective co-reactant but also a morphologic regulator. The morphology of d-MOF changed from a thick sheet to a thin sheet and finally a microflower by controlling the dosage of DEAEA. Linking emitter and co-reactant in a MOF structure, the d-MOF exhibited an efficient intramolecular electron transfer process, with a strong and ultra-stable ECL performance without any extra co-reactants compared with the DPA ligand or the Zn-DPA single ligand MOF (s-MOF). Furthermore, an ECL resonance energy transfer (ECL-RET) biosensor was fabricated using d-MOF as donor, and 6-carboxy-4', 5'-dichloro-2', 7'-dimethoxyfluorescein (JOE) as accepter for the ultra-sensitive detection of miR-21 without additional co-reactant. And with a detection linear range of miR-21 was 100.0 aM to 10.0 pM, with a detection limit of 61.7 aM. This work offers a new perspective for the future design of stable self-enhanced ECL materials.