Metal-organic polyhedra for selective sensing of ribonucleosides through the cooperation of hydrogen-bonding interactions.

The fluorescence recognition of octahedral nanocages M-QT1 (M = Co, Zn) and metallotricycle Pd-QD, that are comprised of luminescence active quinoline groups and several kinds of amide groups, on ribonucleosides was investigated. The amide groups located on the opening windows or inner surface of the polyhedra and polygon, respectively, providing special environments for the size or shape-selective dynamic molecular recognition and amplified the guest-bonding events to produce a measurable output. While the participation of the active CH moiety in hydrogen bonding interactions corresponding to these amide groups caused the M-QT1 polyhedra to exhibit selectivity towards cytidine over other ribonucleosides, the possible two-fold hydrogen bonding interactions between the nucleosides and the amide groups in Pd-QD made the tricycle show a uridine-specific response. All these results demonstrated that these metal-organic architectures having amide groups and functionalized moieties are potential luminescence chemosensors for the selective sensing of special ribonucleosides, through modifying the hydrogen-bonding interactions.