Fluorescence Enhancement of a Metal‐Organic Framework for Ultra‐Efficient Detection of Trace Benzene Vapor

Abstract

Indoor detection of volatile organic compounds (VOCs) concentration is necessary due to the serious toxicity hazards even at trace level. However, physisorbents usually exhibit weak interactions especially in the presence of trace concentrations of VOCs, thus exhibiting poor responsive signal. Herein, we report a new flexible metal-organic framework (MOF) that exhibits interesting pore-opening behavior after immersing in H 2 O. The pore-opening phase shows significant ( � 116 folds) and extremely fast (< 1 minute) fluorescence enhancement after being exposed to saturated benzene vapor. The limit of detection concentration for benzene vapor can be calculated as 0.133 mg L À 1 . Thus this material represents the first MOF to achieve visual detection of trace benzene vapor by the naked eyes. Theoretical calculations and singlecrystal structure reveal that the special "bilateral π-π stacking" interactions between the host and guest, which facilitate electron transfer and greatly enhance the intensity of fluorescence.

Dual-Color Visual Ratiometric Fluorescence Sensing for H2O and D2O Mixtures Using a Hexanuclear Ln(III) Cluster-Based Metal–Organic Framework

“…Fluorescence sensing based on optical signal responses originating from sensor–analyte interactions has attracted considerable attention owing to its fast response, high sensitivity, and real-time detection . Fluorescent metal–organic frameworks (MOFs) are a type of hot sensor material owing to their structural and functional controllable design that can facilitate the molecular interaction between the analyte and MOF skeleton, thus resulting in a distinctively optical signal response. However, to the best of our knowledge, very few studies have reported on fluorescent MOFs for D 2 O detection. Humphrey et al examined the Eu­(III), Tb­(III), and Gd­(III) mix-coordinated isomorphic arylphosphine ligand-based PCM-22 for H 2 O detection in D 2 O .…”