Porphyrin-based porous organic polymers enriched with Fe3O4 nanoparticles as electrosensors for the detection of endocrine disrupting chemicals in water

Abstract

Endocrine disrupting chemicals (EDCs) are commonly found in products such as pesticides, plastics, and pharmaceuticals. These chemicals are of significant concern due to their potential to disrupt the endocrine system, which plays essential roles in growth and reproduction. The detection of EDCs in water requires extensive equipment training and is expensive; therefore, it remains a significant challenge. Various catalysts such as multiwalled carbon nanotubes and graphene has been used as sensors to detect EDCs but porous organic polymers (POPs) and Porphyrin-based POPs (Py-POPs) have gained interest in electrochemical research owing to their porosity, stability, and tuneable structure. The structure of POPs depends on the synthetic method, the monomer used, and reaction conditions. Porphyrins are cyclic tetrapyrroles that consist of a conjugated π-electron system. Due to this conjugation, Py-POPs are stable structures that can coordinate metal ions. Metalated porphyrin-based POPs (MPy-POPs) are redox-active and chemically stable with improved electrochemical performance. In light of this, metalated porphyrin-based POPs (MPy-POPs) were used as sensing platforms for the detection of 2-phenylphenol, an endocrine disrupting chemical. Iron and zinc Py-POPs were synthesized and enriched with Fe3O4 nanoparticles to form nanocomposite materials. The morphological and structural characteristics of the composites were analysed using a variety of techniques, which includes ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), tunnel electron microscopy (TEM) and energy dispersive X-ray (EDX) analysis. The synthesized composites had spherical morphology. The Fe3O4@MPy-POP catalysts were used for the electrocatalytic detection of 2-phenylphenol. Catalytic currents ranged between 24.7 µA and 41.5 µA, with peak potentials between 0.61 V and 0.65 V. The limit of detection ranged from 0.75 mM to 2.6 mM for the redox active catalysts. Real sample analysis using sunblock and apple peels were analyzed for the detection abilities of the synthesized catalysts. This study shows that these composites are promising materials for the detection endocrine disrupting chemicals in water.