CoxFe3−xO4 hierarchical nanocubes as peroxidase mimetics and their applications in H2O2 and glucose detection

Abstract

A facile approach was proposed for the synthesis of hierarchical Co_xFe_3−xO₄ nanocubes (CF nanocubes), using Prussian Blue (PB) as precursor. The method consists of the synthesis of hierarchical cobalt–iron Prussian blue analogues (PBAs) through the reaction of PB nanocubes with CoCl₂ in a water bath and subsequently calcining the corresponding PBA precursor. The obtained CF nanocubes were characterized using transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and N₂ adsorption–desorption isotherm measurements. It is found that the hierarchical CF nanocubes have a large specific surface area (108 m² g⁻¹). Considering the hierarchical structure and the doping of Co in Fe₃O₄ are beneficial for the catalytic activity of the catalyst, an efficient and simple colorimetric biosensor for H₂O₂ and glucose was fabricated using CF nanocubes as a peroxidase mimetic. The good catalytic activity and low-cost make the hierarchical CF nanocubes a useful biocatalyst for a wide range of potential applications in medicine and biotechnology.