Sheathed in situ heteroepitaxial growth metal-organic framework probe for detection of polycyclic aromatic hydrocarbons in river water and living fish

Exploring the presence of polycyclic aromatic hydrocarbons (PAHs) in aquatic environment is an important task. Metal-organic frameworks (MOF) are commonly used as sorbents for enriching PAHs but their crystal synthesis, sorbent preparation and robustness remain challenging. In the present study, under mild conditions, a novel sheathed MOF fiber coating was fabricated via in situ heteroepitaxial growth of copper-2,5-diaminoterephthalate (Cu-DAT) crystals and subsequent polyimide (PI) sheath. The copper hydroxide nanotubes were first synthesized on the copper wire to provide a substrate for further in situ heteroepitaxial Cu-DAT growth, and the coating was then sheathed with PI via a simple dip-coating procedure. The well-ranged copper hydroxide nanotubes, the unique adsorption property of Cu-DAT, and the PI sheath, the prepared fiber all contributed to a successful solid-phase microextraction (SPME) device for detecting PAHs. Results demonstrated that the SPME methods using the novel fiber possessed great sensitivity, wide linear range, good reproducibility, and the robustness was significantly improved with PI sheath. The novel SPME material was successfully applied for detection of PAHs in river water samples and in vivo detection of PAHs in fish dorsal muscle. In general, this study explored an effective and convenient method to prepare high-efficient MOF-based SPME fiber for PAHs analysis in complex environmental water samples and living organisms via in situ growth and polymer sheath. (C) 2020 Elsevier B.V. All rights reserved.