Modulating the optical properties of the AIE fluophor confined within UiO-66's nanochannels for chemical sensing

Transformation of aggregation induced emission (AIE) molecules into functional materials can greatly tune their fluorescence properties and expand their related potential applications. Here, we demonstrate a facile strategy to modulate the fluorescence properties of AIE molecules by confining them within the nanochannels of metal–organic frameworks (MOFs). AIE molecules (4,4′-(hydrazine-1,2-diylidene bis(methanylylidene)) bis(3-hydroxybenzoic acid), HDBB) with pH-dependent emission were successfully integrated into UiO-66 resulting in a UiO-66⊃HDBB complex while maintaining the crystal structure by the host–guest process. The fluorescence properties of HDBB can be modulated by virtue of the unique nanospace confining effect. Furthermore, UiO-66⊃HDBB was used as a sensitive and selective fluorescent probe for Cu2+ detection in aqueous solution. This study provides a facile strategy for the construction of high performance AIE based luminescent materials with adjustable properties for potential applications.