Smart Stimulation Response of a Pyrene-Based Lanthanide(III) MOF: Fluorescence Enhancement to HX (F and Cl) or R-COOH and Artificial Applicable Film on HCl Vapor Sensing.

Toxic acids produced by industries are major hazards to the environment and human health, and luminescent pyrene-based crystalline metal-organic frameworks (MOFs) demonstrate promising performance in the detection of toxic acids. Herein, two novel isostructural 3D porous lanthanide MOFs, HO·[Ln(TBAPy)(μ-HO)(OH)]·2DMA·2Diox·6.5HO (Ln = Pr () and Ce (); HTBAPy (1,3,6,8-tetrakis(-benzoic acid)pyrene); and DMA: ,-dimethylacetamide) were synthesized, which showed topology. Based on the protonation and hydrogen bond mechanism, complex could be used as a fluorescence recognition sensor for HX (X = F, Cl, Br, and I) acid solutions with different luminescence behaviors. It is worth noting that complex exhibited high sensitivity in the fluorescence enhancement sensing of hydrofluoric acid, oxalic acid, and trichloroacetic acid. In particular, complex had a low limit of detection (LOD) for OA (0.1 μM) and was applied to real monitoring of orange fruit samples. In addition, the PVA@ film could selectively, sensitively, and quantitatively respond to hydrochloric acid (HCl) vapor through fluorescent quenching; due to its protonation and adsorption capacity, the LOD was 0.18 ppm. Therefore, the portable optical device, the PVA@ film, can detect HCl gas in trace amounts, achieving the ultimate goal of real-time and rapid detection, which has potential application value for industrial production safety.