LAUSR

The integration of metal–organic frameworks (MOFs) and functionalized magnetic graphene (magG) to form composites has attracted growing attention due to the superimposed properties and extensive applications. However, so far it has not been possible to functionalize but only uncover magnetic graphene to protect its own properties with MOFs. In this work, a template protection–sacrifice (TPS) strategy has been successfully developed to functionalize but also uncover magnetic graphene. SiO2 was used not only a protective shell for magnetic graphene, but also as a sacrificial template to form a two-layer structure. The obtained zeolitic imidazolate framework-8 functionalized magnetic graphene (magG@ZIF-8) composites showed excellent extraction efficiency and promising reusability for phthalate esters with linearity that was between 50 and 8000 ng mL−1, recoveries that varied from 92.1 to 105.3%, relative standard deviation (RSDs) for intra-day and inter-day that was 1.8–4.2% and 3.5–6.5%, limit of detection (LOD) that was in the range of 0.003–0.01 ng mL−1 (S/N = 3), and LOQ that varied from 0.1 to 0.5 ng mL−1 (S/N = 10). More encouragingly, the new synthesized composites were used to analyze nine phthalates in human plasma samples. Our TPS strategy may also provide a new avenue for functionalizing and/or uncovering substrate support materials.