Discrimination of Various Amine Vapors by a Triemissive Metal-Organic Framework Composite via the Combination of a Three-Dimensional Ratiometric Approach and a Confinement-Induced Enhancement Effect.

Multiemissive sensors are being actively pursued, because of their ratiometric luminescent detection capabilities, which demonstrates better sensitivity and selectivity than conventional single-emission sensors. Herein, we present a trichromatic white-light-emitting metal-organic framework (MOF) composite (Z3) by simultaneously incorporating red/green-emitting Pt/Ru complex cations into porous blue-emitting bio-MOF-1 through post-synthetic modification. With the help of a three-dimensional (3-D) dual-ratiometric luminescence recognition method, and unique turn-on responses of the red emission toward amine compounds (ACs), including NH3 and aliphatic amines, via confinement-induced luminescence enhancement effect, Z3 can work as a dual-ratiometric luminescent sensor for discrimination of 7 out of 11 AC vapors. This work not only provides a new AC sensing mechanism (confinement effect) that can induce a "turn-on" response but also proves that the accuracy and selectivity of composite sensor can be greatly improved through the combination of 3-D recognition method and the confinement effect. Thus, it open up fresh opportunities to develop composite sensors with excellent sensing and differentiating ability.