From Smartphone Assisted Sensing of Acid and Base Vapor to Antibacterial and Antibiofilm Activity: A Case Study of a FRET Pair Encapsulated Inside ZIF‐8

In the current work, we investigated the Förster resonance energy transfer between an established pair of dyes fluorescein and rhodamine‐B encapsulated in ZIF‐8 metal organic framework (MOF) (RhB+Fl@ZIF‐8). The composite can successfully detect acid and base vapor within 10 min at ambient conditions, triggered by an optical change realized by the aid of a smartphone and a handheld UV torch. The change in color can be understood by any color matching applications available on the smartphone platforms. RhB+Fl@ZIF‐8 also shows considerable antibacterial activity (75.19%) whereas the individual composites of ZIF‐8 with fluorescein (63.81%) and rhodamine‐B (65.42%) showed lower improvement in antibacterial activity of pristine ZIF‐8 (66.64%). The current work opens up new avenues for designing multiutility MOF‐based materials for dual applications in optical sensing of acid and base vapor and as antibacterial agents.