Facile Synthesis of Tuneable Zinc-based Metal-Organic Frameworks for Biological Application

Abstract

Zinc-based metal-organic frameworks (ZnMOFs) have been attracting attention as versatile materials for bioanalytical and biomedical applications owing to their structural tunability, biocompatibility, and potential for integration with molecular recognition elements. In this study, we report a facile aqueous synthesis of ZnMOFs using adenine as nucleobase linker and explored their multifunctionality for aptamer-based biological applications. The resulting ZnMOF particles exhibited controllable size and tunable surface charge through post-synthesis treatments such as polystyrene sulfonate and sonication. Density functional theory calculations revealed Zn-N coordination and Zn-cluster formation underpinning the inherently amorphous framework architecture. Notably, the system enables direct coordination-driven incorporation of aptamers via their poly-adenine tails during particle formation. Incorporation of ZnMOF with a VCAM-1 aptamer enhanced fluorescent signals in immunofluorescence assay and flow cytometry, providing a sensitive platform for biomolecular detection. Additionally, ZnMOF decorated with a CD63 aptamer enabled selective exosome capture and gentle recovery, maintaining exosomal integrity for downstream quantitative reverse transcriptase loop-mediated isothermal amplification (qRT-LAMP) of exosomal RNA biomarkers. Collectively, our findings demonstrate ZnMOFs as a simple, versatile, tuneable platforms for aptamer-based sensing and exosome isolation, with broad potential for biological and biomedical applications.