Core-Shell Structured Magnetic Covalent Organic Framework Nanocomposites for Triclosan and Triclocarban Adsorption

Triclosan (TCS) and triclocarban (TCC) are widely used as bactericides in personal-care products. They are frequently found in environmental water and have the potential to cause a number of environmental and human health problems. In this study, we investigated adsorption and magnetic extraction for efficient removal of TCS and TCC from water and serum samples by core-shell structured magnetic covalent organic framework nanocomposites (Fe₃O₄@COFs). The as-prepared Fe₃O₄@COFs was fabricated on the Fe₃O₄ nanoparticles in situ growth strategy at room temperature via condensation reaction of 1,3,5-tris(4-aminophenyl) benzene (TAPB) and terephthaldicarbox-aldehyde (TPA) in the presence of dimethyl sulfoxide (DMSO). The whole process of adsorption was monitored by ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis with high sensitivity. The adsorption behaviors showed high adsorption capacity and fast adsorption. Furthermore, the adsorption performance through Langmuir and Freundlich isotherms showed multilayer adsorption through the interactions of space embedding effect, van der Waals forces, and benzene ring π-π stacking at a low concentration range and monolayer adsorption through strong π-π stacking at a high concentration range between the interface of TCS or TCC and Fe₃O₄@COFs at a high concentration range. Results indicated that the adsorption of TCS and TCC onto Fe₃O₄@COFs can be better represented by the pseudo-second-order model. Good removal efficiencies (82.3∼95.4%) and recoveries (92.9∼109.5%) of TCS and TCC in fetal bovine serum (FBS) and reusability at least 10 times were achieved. The Fe₃O₄@COFs exhibited high stability and excellent performance for the removal of TCS and TCC from water and biological samples. The results presented here thus reveal the exceptional potential of COFs for high-efficient environmental remediation.