Porphyrin-Based Porous Organic Polymer as Peroxidase Mimics for Sulfide-Ion Colorimetric Sensing
Yanhong Li, Yishan Fang, Wenqiang Gao, Xiaojun Guo, Xiaomei Zhang
Abstract
The effective synthesis of functional nanoplatforms for simple, selective, and sensitive hydrogen sulfide detection has received significant attention because of the toxicity of hydrogen sulfide. Here, a new porphyrin-based porous organic polymer, FePPOPEPA, was fabricated through a Pd-/CuI-catalyzed Sonogashira cross-coupling reaction between tris(4-ethynylphenyl)amine and iron(III) 5,10,15,20-tetrakis-(4′-bromophenyl)porphyrinato (FeTBrPP). Results showed that FePPOPEPA has a porous framework, high BET surface areas, wide pore size distribution, abundant surface catalytic active sites, and excellent stability as well as reusability. In the presence of H2O2, FePPOPEPA showed high peroxidase-like activity toward 3,3′,5,5′-tetramethylbenzidine. Based on these findings, FePPOPEPA was used for the first time as an efficient colorimetric probe for sensitive and selective detection of sulfide ions with a low detection limit (0.013 μM) within 3 min. The feasibility of this method for real water samples was validated via a standard addition experiment. Moreover, the catalytic inhibition mechanism of S2– to FePPOPEPA was disclosed by X-ray photoelectron spectroscopy spectra.