Two-Dimensional Metal-Organic Framework Nanosheets as a Dual Ratiometric and Turn-off Luminescent Probe.

Current research on metal-organic framework (MOF) luminescent sensing probes focuses on the design of three-dimensional bulk-sized MOFs that in return limits their up-close interactions with targeted guest molecules. In this work, we report a two-dimensional (2D) copper-based metal-organic framework, namely, AUBM-6, synthesized via solvothermal method from isonicotinic acid linker and copper(II) ion. The resulting 2D-layered MOF crystals were highly fluorescent in their exfoliated form and, therefore, explored for detecting several solvents, where a ratiometric selectivity was shown toward acetone. Metal ion sensing was also performed, by which fluorescent detection was observed to have the highest turn-off quenching efficiency toward Pd ²⁺ .