Perylene diimide‐modified magnetic γ‐Fe₂O₃/CeO₂ nanoparticles as peroxidase mimics for highly sensitive colorimetric detection of Vitamin C

Abstract

Perylene diimide‐modified magnetic γ‐Fe2O3/CeO2 nanoparticles (γ‐Fe2O3/CeO2‐PDI) were prepared and exhibited excellent peroxidase‐like activity. The samples were characterized by HR‐TEM, XRD, Raman, N2 adsorption, magnetic strength and XPS. The obtained γ‐Fe2O3/CeO2‐PDI had size of 10~20 nm with high specific surface area of 77 m2/g, and could be easily separated from the aqueous solution by using a magnet, which are in favor of its practical application. Due to the decoration of PDI, the γ‐Fe2O3/CeO2‐PDI possessed more surface defects (Ce3+) and active oxygen species than that of γ‐Fe2O3/CeO2, resulting in the outstanding catalytic performance. And the composite catalyst also showed highly sensitive and selectivity toward VC with a limit of detection of 0.45 μM. Based on the fluorescent results, a possible hydroxyl radical (•OH) catalytic mechanism was proposed. It is believed that the as‐prepared γ‐Fe2O3/CeO2‐PDI nanoparticles are promising biosensors applied for biomedical and food analysis.

Nanoceria-Templated Metal Organic Frameworks with Oxidase-Mimicking Activity Boosted by Hexavalent Chromium

“…27 As a costeffective approach, various structures based on CeO 2 were employed to enhance activity, such as the composite materials with noble metals (Au, Ag, and Pt), 28−30 and metal oxides (TiO 2 , Fe 2 O 3 ). 31,32 Fluoride can also be used to enhance the oxidase-like activity of CeO 2 by modulating the surface charge and electron transfer. 22 Coating a molecularly imprinted hydrogel shell can also enhance the nanozyme activity of CeO 2 , and the specificity for substrate has been greatly improved.…”