An ideal platform of light-emitting materials from phenothiazine: facile preparation, tunable red/NIR fluorescence, bent geometry-promoted AIE behaviour and selective lipid-droplet (LD) tracking ability

Abstract

A series of phenothiazine-based red/NIR fluorophores were facilely prepared, which displayed typical aggregation-induced emission (AIE) and solid-state fluorescence with a relatively high fluorescence quantum yield. As a new potential AIE building block, the exact AIE mechanism of the phenothiazine moiety was comprehensively investigated. The naturally bent geometry of the phenothiazine structure induced solid state emission and reduced the dilute state fluorescence simultaneously. In further biological experiments, these dyes could selectively track lipid droplets (LDs) in living HeLa cells with high resolution and selectivity. All these investigations promised a good future for the phenothiazine derivatives as typical AIE building blocks.